diff --git a/ets2panda/checker/ets/utilityTypeHandlers.cpp b/ets2panda/checker/ets/utilityTypeHandlers.cpp
index 22cd11c5f0b9425aa8162f082780511978759540..48967c2d7d01beb6bbf9c480c48fb590f833c00d 100644
--- a/ets2panda/checker/ets/utilityTypeHandlers.cpp
+++ b/ets2panda/checker/ets/utilityTypeHandlers.cpp
@@ -38,6 +38,13 @@ std::optional<ir::TypeNode *> ETSChecker::GetUtilityTypeTypeParamNode(
     return typeParams->Params().front();
 }
 
+static bool ValidBaseTypeOfRequiredAndPartial(Type *baseType)
+{
+    Type *type = baseType->MaybeBaseTypeOfGradualType();
+    return type->IsETSObjectType() && (type->AsETSObjectType()->HasObjectFlag(ETSObjectFlags::INTERFACE) ||
+                                       type->AsETSObjectType()->HasObjectFlag(ETSObjectFlags::CLASS));
+}
+
 Type *ETSChecker::HandleUtilityTypeParameterNode(const ir::TSTypeParameterInstantiation *const typeParams,
                                                  const ir::Identifier *const ident)
 {
@@ -66,6 +73,13 @@ Type *ETSChecker::HandleUtilityTypeParameterNode(const ir::TSTypeParameterInstan
         return baseType;
     }
 
+    if ((utilityType == compiler::Signatures::PARTIAL_TYPE_NAME ||
+         utilityType == compiler::Signatures::REQUIRED_TYPE_NAME) &&
+        !ValidBaseTypeOfRequiredAndPartial(baseType)) {
+        LogError(diagnostic::MUST_BE_CLASS_INTERFACE_TYPE, {utilityType}, typeParams->Start());
+        return GlobalTypeError();
+    }
+
     if (utilityType == compiler::Signatures::PARTIAL_TYPE_NAME) {
         // SUPPRESS_CSA_NEXTLINE(alpha.core.AllocatorETSCheckerHint)
         return CreatePartialType(baseType);
diff --git a/ets2panda/test/ast/compiler/ets/Partial_utility_type_0.ets b/ets2panda/test/ast/compiler/ets/Partial_utility_type_0.ets
new file mode 100644
index 0000000000000000000000000000000000000000..b72c198c605052e4f6589d7b3d89bd93663db680
--- /dev/null
+++ b/ets2panda/test/ast/compiler/ets/Partial_utility_type_0.ets
@@ -0,0 +1,32 @@
+/*
+ * Copyright (c) 2025 Huawei Device Co., Ltd.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+class A {}
+class B {}
+
+function foo<T>() {
+    let x1: Partial<void> = {}
+    let x2: Partial<A | B> = {}
+    let x3: Partial<T> = {}
+    let x4: Partial<undefined> = {}
+    let x5: Partial<null> = {}
+}
+
+
+/* @@? 20:20 Error TypeError: T in Partial<T> must be a class or an interface type. */
+/* @@? 21:20 Error TypeError: T in Partial<T> must be a class or an interface type. */
+/* @@? 22:20 Error TypeError: T in Partial<T> must be a class or an interface type. */
+/* @@? 23:20 Error TypeError: T in Partial<T> must be a class or an interface type. */
+/* @@? 24:20 Error TypeError: T in Partial<T> must be a class or an interface type. */
diff --git a/ets2panda/test/ast/compiler/ets/Required_utility_type_0.ets b/ets2panda/test/ast/compiler/ets/Required_utility_type_0.ets
new file mode 100644
index 0000000000000000000000000000000000000000..00fd2a2a6e27e1da5b191c8875782731d22a791c
--- /dev/null
+++ b/ets2panda/test/ast/compiler/ets/Required_utility_type_0.ets
@@ -0,0 +1,33 @@
+/*
+ * Copyright (c) 2025 Huawei Device Co., Ltd.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+class A {}
+class B {}
+
+function foo<T>() {
+    let x1: Partial<void> = {}
+    let x2: Partial<A | B> = {}
+    let x3: Partial<T> = {}
+    let x4: Partial<undefined> = {}
+    let x5: Partial<null> = {}
+}
+
+
+
+/* @@? 20:20 Error TypeError: T in Partial<T> must be a class or an interface type. */
+/* @@? 21:20 Error TypeError: T in Partial<T> must be a class or an interface type. */
+/* @@? 22:20 Error TypeError: T in Partial<T> must be a class or an interface type. */
+/* @@? 23:20 Error TypeError: T in Partial<T> must be a class or an interface type. */
+/* @@? 24:20 Error TypeError: T in Partial<T> must be a class or an interface type. */
diff --git a/ets2panda/test/ast/compiler/ets/partialTypeParameterParamInfer.ets b/ets2panda/test/ast/compiler/ets/partialTypeParameterParamInfer.ets
new file mode 100644
index 0000000000000000000000000000000000000000..19aeb05f0b5911ee21e006696ae7fbd91d55c24d
--- /dev/null
+++ b/ets2panda/test/ast/compiler/ets/partialTypeParameterParamInfer.ets
@@ -0,0 +1,18 @@
+/*
+ * Copyright (c) 2025 Huawei Device Co., Ltd.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+class instanceof{
+  a : string = "15";
+}
diff --git a/ets2panda/test/ast/compiler/ets/partialType_check_in_RemoveUndefinedType.ets b/ets2panda/test/ast/compiler/ets/partialType_check_in_RemoveUndefinedType.ets
index 2b6557074b07ccbedd8b296b0c99f794a80e98c9..abe625355b83a683c9fa7ee6b74220d7e7bc1de0 100644
--- a/ets2panda/test/ast/compiler/ets/partialType_check_in_RemoveUndefinedType.ets
+++ b/ets2panda/test/ast/compiler/ets/partialType_check_in_RemoveUndefinedType.ets
@@ -21,6 +21,7 @@ function main() {
   genericFunc<{a: number, b: string}>({a: 1})
 }
 
+/* @@? 16:35 Error TypeError: T in Partial<T> must be a class or an interface type. */
 /* @@? 21:3 Error TypeError: Bad operand type, the types of the operands must be numeric, same enumeration, or boolean type. */
 /* @@? 21:15 Error TypeError: need to specify target type for class composite */
 /* @@? 21:38 Error TypeError: need to specify target type for class composite */
diff --git a/ets2panda/test/ast/compiler/ets/requiredType_10_neg.ets b/ets2panda/test/ast/compiler/ets/requiredType_10_neg.ets
index 98320d2d4ce205791760ad66c13b7a6bfb36b365..cc8b0e626ca83e7cf5c1a0c85589709f8bded498 100644
--- a/ets2panda/test/ast/compiler/ets/requiredType_10_neg.ets
+++ b/ets2panda/test/ast/compiler/ets/requiredType_10_neg.ets
@@ -25,4 +25,4 @@ function main(): void {
     let req_a: A<B> = {fld: /* @@ label */{}};
 }
 
-/* @@@ label Error TypeError: Class property 'b_fld' needs to be initialized for Required<B>.  */
+/* @@? 21:18 Error TypeError: T in Required<T> must be a class or an interface type. */
diff --git a/ets2panda/test/ast/compiler/ets/union_type_of_partial_type.ets b/ets2panda/test/ast/compiler/ets/union_type_of_partial_type.ets
index b024428363cc3f69df19ac62f9c781c0332e5f3f..e4ea92495b82b4c51bb4f9c482368c1fc0edba7c 100644
--- a/ets2panda/test/ast/compiler/ets/union_type_of_partial_type.ets
+++ b/ets2panda/test/ast/compiler/ets/union_type_of_partial_type.ets
@@ -21,6 +21,7 @@ abstract class A<T extends A<T>>{
 /* @@? 16:9 Error SyntaxError: Parameter declaration should have an explicit type annotation. */
 /* @@? 16:9 Error SyntaxError: Unexpected token, expected ',' or ')'. */
 /* @@? 16:12 Error SyntaxError: Unexpected token ','. */
+/* @@? 16:27 Error TypeError: T in Partial<T> must be a class or an interface type. */
 /* @@? 16:42 Error SyntaxError: Unexpected token ')'. */
 /* @@? 16:43 Error SyntaxError: Unexpected token ':'. */
 /* @@? 16:45 Error SyntaxError: void is a predefined type, cannot be used as an identifier */
diff --git a/ets2panda/test/ast/compiler/ets/unresolve_class_with_type_infer.ets b/ets2panda/test/ast/compiler/ets/unresolve_class_with_type_infer.ets
index 9347301cc3f96cac0dba997c2b30dd0fec9a5b9e..472597e3c531be5f6c8824116dfa8a1217156688 100644
--- a/ets2panda/test/ast/compiler/ets/unresolve_class_with_type_infer.ets
+++ b/ets2panda/test/ast/compiler/ets/unresolve_class_with_type_infer.ets
@@ -20,3 +20,6 @@ function foo<T extends Record<string, A>>(record: Record<string, Partial<T>>){
 foo({})
 
 /* @@? 16:39 Error TypeError: Cannot find type 'A'. */
+/* @@? 16:73 Error TypeError: T in Partial<T> must be a class or an interface type. */
+/* @@? 20:1 Error TypeError: No matching call signature for foo(...) */
+/* @@? 20:5 Error TypeError: need to specify target type for class composite */
diff --git a/ets2panda/test/ast/compiler/ets/utility_type_can_not_found_etsobjecttype.ets b/ets2panda/test/ast/compiler/ets/utility_type_can_not_found_etsobjecttype.ets
index f549a860b8ab50e6349d41dcc5729825bdb46024..dacc830f5d11bc033b978db592a19c6cc8dd35c9 100644
--- a/ets2panda/test/ast/compiler/ets/utility_type_can_not_found_etsobjecttype.ets
+++ b/ets2panda/test/ast/compiler/ets/utility_type_can_not_found_etsobjecttype.ets
@@ -26,4 +26,5 @@ class X<T extends BaseObject> {
 }
 
 /* @@? 16:34 Error TypeError: Cannot find type 'any'. */
-/* @@? 23:14 Error TypeError: Target type for class composite needs to be an object type, found 'T' */
\ No newline at end of file
+/* @@? 21:29 Error TypeError: T in Partial<T> must be a class or an interface type. */
+/* @@? 23:14 Error TypeError: Target type for class composite needs to be an object type, found 'T' */
diff --git a/ets2panda/test/ast/parser/ets/partialType_4.ets b/ets2panda/test/ast/parser/ets/partialType_4.ets
index 8cf429864d6297082d81862624ed49379eee2e35..138a81089d6ff0da4679186406e0ce935caab563 100644
--- a/ets2panda/test/ast/parser/ets/partialType_4.ets
+++ b/ets2panda/test/ast/parser/ets/partialType_4.ets
@@ -79,4 +79,9 @@ class A<T extends A<T>>{
     bar(initializers: Partial<T>): void {}
 }
 
-/* @@@ label Error TypeError: Type 'S' cannot be assigned to type 'T|undefined'  */
+/* @@? 39:142 Error TypeError: T in Partial<T> must be a class or an interface type. */
+/* @@? 49:55 Error TypeError: T in Partial<T> must be a class or an interface type. */
+/* @@? 51:51 Error TypeError: T in Partial<T> must be a class or an interface type. */
+/* @@? 53:86 Error TypeError: T in Partial<T> must be a class or an interface type. */
+/* @@? 75:55 Error TypeError: T in Partial<T> must be a class or an interface type. */
+/* @@? 79:30 Error TypeError: T in Partial<T> must be a class or an interface type. */
diff --git a/ets2panda/test/ast/parser/ets/partial_type_param1.ets b/ets2panda/test/ast/parser/ets/partial_type_param1.ets
index de1e4ed9c53f306497097be4b73b822f039067ce..0ff07bf635902a8bde714b6eae5170e586c9577a 100644
--- a/ets2panda/test/ast/parser/ets/partial_type_param1.ets
+++ b/ets2panda/test/ast/parser/ets/partial_type_param1.ets
@@ -36,4 +36,6 @@ function generic<T extends I>(t: Partial<T>): boolean {
 function main() {
     // Test that {i: 1} is accepted as Partial<CI>
     generic<CI>({i: 1});
-}
\ No newline at end of file
+}/* @@? 32:41 Error TypeError: T in Partial<T> must be a class or an interface type. */
+/* @@? 38:5 Error TypeError: No matching call signature for generic(...) */
+/* @@? 38:17 Error TypeError: need to specify target type for class composite */
diff --git a/ets2panda/test/ast/parser/ets/partial_type_param2.ets b/ets2panda/test/ast/parser/ets/partial_type_param2.ets
index e0ea578664753a4d4169f538f75324157538eda3..7dbb5c559d86caf893bcae792c7a25b24ee8142a 100644
--- a/ets2panda/test/ast/parser/ets/partial_type_param2.ets
+++ b/ets2panda/test/ast/parser/ets/partial_type_param2.ets
@@ -34,4 +34,6 @@ function foo<T extends I>(i: Partial<T>): number {
 function main() {
   // Test case: only 'i' is provided, 'j' is omitted
   foo<I>({ i: 5 });
-}
\ No newline at end of file
+}/* @@? 21:37 Error TypeError: T in Partial<T> must be a class or an interface type. */
+/* @@? 36:3 Error TypeError: No matching call signature for foo(...) */
+/* @@? 36:10 Error TypeError: need to specify target type for class composite */
diff --git a/ets2panda/test/ast/parser/ets/type_from_utility_type.ets b/ets2panda/test/ast/parser/ets/type_from_utility_type.ets
index fd5724ec64144391b1b695595763a83ec5370f82..dd7dd59374f7b8d5957cc0806b7d318a3f341edd 100644
--- a/ets2panda/test/ast/parser/ets/type_from_utility_type.ets
+++ b/ets2panda/test/ast/parser/ets/type_from_utility_type.ets
@@ -33,6 +33,9 @@
  }
  
   /* @@? 30:19 Error TypeError: Bad operand type, the types of the operands must be numeric, same enumeration, or boolean type. */
+/* @@? 17:37 Error TypeError: T in Partial<T> must be a class or an interface type. */
+/* @@? 21:39 Error TypeError: T in Required<T> must be a class or an interface type. */
+/* @@? 30:19 Error TypeError: Bad operand type, the types of the operands must be numeric, same enumeration, or boolean type. */
 /* @@? 30:29 Error TypeError: No static $_invoke method and static $_instantiate method in Record. Record() is not allowed. */
 /* @@? 30:29 Error TypeError: Type 'Record<K,V>' has no call signatures. */
 /* @@? 31:38 Error TypeError: Type argument 'Array<String>' should be a subtype of 'Numeric|String|BaseEnum<Int>|BaseEnum<Long>|BaseEnum<String>'-constraint */
diff --git a/ets2panda/test/benchmarks/bench_1.ets b/ets2panda/test/benchmarks/bench_1.ets
index a200b8c29d28a7b0b7332f96f72f3e5dbe958c30..9803462714ebd80a6674beca0344537b0ec1b8b7 100644
--- a/ets2panda/test/benchmarks/bench_1.ets
+++ b/ets2panda/test/benchmarks/bench_1.ets
@@ -415,7 +415,7 @@ function assert_o5(v: Object | null | undefined) { arktest.assertTrue(v !== null
 function assert_npe5(f: () => void) {
     try {
         f();
-    } catch (e: NullPointerError) {
+    } catch (e) {
         return;
     }
     arktest.assertTrue(false,  "npe was not thrown")
@@ -761,16 +761,16 @@ function test_38(): void {
 
 // -----------------------------------------------
 
-class Class68<T8> {
+class Class68 {
     mmeb: Number = 2;
-    foo(a0: Partial<T8>){
+    foo(a0: Partial<Class78>){
         if(this.mmeb == 3){
             return;
         }
 
         this.bar(a0);
     }
-    bar(a0: Partial<T8>){
+    bar(a0: Partial<Class78>){
         this.mmeb = 3;
         this.foo(a0);
     }
@@ -778,15 +778,15 @@ class Class68<T8> {
 
 class Class78 { fld: Number = 6;}
 
-class Class88 <T8 extends Class78> {
-    baz(a0: Partial<T8>){
+class Class88 {
+    baz(a0: Partial<Class78>){
         a0.fld = undefined;
     }
 }
 
 function test_48(): void {
     let class7_partial: Partial<Class78> = {fld: 8};
-    let class6_original: Class68<Class78> = new Class68<Class78>();
+    let class6_original: Class68 = new Class68();
     class6_original.foo(class7_partial);
 }
 
@@ -818,7 +818,7 @@ function test_58(): void {
 
 class C33  {
   bar(): string {
-    return "Class C33";
+    return "";
   }
 }
 
@@ -994,13 +994,14 @@ function bar35(x: C35|null|undefined, y: boolean, z: boolean): string {
 // SmartCast_06.ets
 // ---------------------------------------------------------------------------------------------------------------------
 
-function foo36(x: int): string
+function foo36(x: int): string | undefined
 {
   let rc: string|undefined = "default";
 
   label1: switch(x) {
     case 0:
        rc = "case 0";
+       break;
     case 1: {
        let rc1: string|undefined = ():string => {return "case 1";}();
        label2: switch(rc) {
@@ -1022,10 +1023,12 @@ function foo36(x: int): string
        break;
     case 4:
        rc = undefined;
-    default:
-       return rc != null ? rc :"case 4"
+       break;
     case 5:
        rc = "case 5";
+       break;
+    default:
+       return rc != null ? rc :"case 4"
   }
 
   return rc;
@@ -1047,10 +1050,12 @@ function foo37(flag37: boolean): int {
     if (flag37) {
       throw new Error();
     }
-  } catch(ex: NullPointerError) {
-    z = 2;
   } catch(ex) {
-    w = undefined;
+    if (ex instanceof NullPointerError) {
+      z = 2;
+    } else {
+      w = undefined
+    }
   }
 
   return x + y! + z + w!;
diff --git a/ets2panda/test/compiler/ets/requiredType_11-expected.txt b/ets2panda/test/compiler/ets/requiredType_11-expected.txt
index 41e27345ba492fd631ba8f586d432b425cd9c39f..4211a0eeddb1b7ccea45b5400a25c62495f05a2d 100644
--- a/ets2panda/test/compiler/ets/requiredType_11-expected.txt
+++ b/ets2panda/test/compiler/ets/requiredType_11-expected.txt
@@ -1333,3 +1333,4 @@
     }
   }
 }
+TypeError: T in Required<T> must be a class or an interface type. [requiredType_11.ets:21:18]
diff --git a/ets2panda/test/compiler/ets/requiredType_9-expected.txt b/ets2panda/test/compiler/ets/requiredType_9-expected.txt
index 2b7ed4053ec366dbb518a6dcca46e30c5f78d359..a80cb5e8d43fa76bc0acc6479968f22cf775ce28 100644
--- a/ets2panda/test/compiler/ets/requiredType_9-expected.txt
+++ b/ets2panda/test/compiler/ets/requiredType_9-expected.txt
@@ -1743,3 +1743,5 @@
     }
   }
 }
+TypeError: T in Required<T> must be a class or an interface type. [requiredType_9.ets:22:19]
+TypeError: T in Required<T> must be a class or an interface type. [requiredType_9.ets:23:19]
diff --git a/ets2panda/test/runtime/ets/too_many_async.ets b/ets2panda/test/runtime/ets/fuzz/too_many_async.ets
similarity index 100%
rename from ets2panda/test/runtime/ets/too_many_async.ets
rename to ets2panda/test/runtime/ets/fuzz/too_many_async.ets
diff --git a/ets2panda/test/runtime/ets/too_many_await.ets b/ets2panda/test/runtime/ets/fuzz/too_many_await.ets
similarity index 100%
rename from ets2panda/test/runtime/ets/too_many_await.ets
rename to ets2panda/test/runtime/ets/fuzz/too_many_await.ets
diff --git a/ets2panda/test/runtime/ets/too_many_call_expr.ets b/ets2panda/test/runtime/ets/fuzz/too_many_call_expr.ets
similarity index 100%
rename from ets2panda/test/runtime/ets/too_many_call_expr.ets
rename to ets2panda/test/runtime/ets/fuzz/too_many_call_expr.ets
diff --git a/ets2panda/test/runtime/ets/too_many_left_brace.ets b/ets2panda/test/runtime/ets/fuzz/too_many_left_brace.ets
similarity index 100%
rename from ets2panda/test/runtime/ets/too_many_left_brace.ets
rename to ets2panda/test/runtime/ets/fuzz/too_many_left_brace.ets
diff --git a/ets2panda/test/runtime/ets/too_many_left_square_brackets.ets b/ets2panda/test/runtime/ets/fuzz/too_many_left_square_brackets.ets
similarity index 100%
rename from ets2panda/test/runtime/ets/too_many_left_square_brackets.ets
rename to ets2panda/test/runtime/ets/fuzz/too_many_left_square_brackets.ets
diff --git a/ets2panda/test/runtime/ets/too_many_new_expr.ets b/ets2panda/test/runtime/ets/fuzz/too_many_new_expr.ets
similarity index 100%
rename from ets2panda/test/runtime/ets/too_many_new_expr.ets
rename to ets2panda/test/runtime/ets/fuzz/too_many_new_expr.ets
diff --git a/ets2panda/test/runtime/ets/partialTypeRuntime_2.ets b/ets2panda/test/runtime/ets/partialTypeRuntime_2.ets
index ceac96c37e0fe1e3800526653b7c5dfe1f940f18..a59ba113aeb9fb19ddf4190bf40d7d52b68cc9d4 100644
--- a/ets2panda/test/runtime/ets/partialTypeRuntime_2.ets
+++ b/ets2panda/test/runtime/ets/partialTypeRuntime_2.ets
@@ -70,16 +70,16 @@ function test_3(): void {
 
 // -----------------------------------------------
 
-class Class6<T> {
+class Class6 {
     mmeb: Number = 2;
-    foo(a0: Partial<T>){
+    foo(a0: Partial<Class7>){
         if(this.mmeb == 3){
             return;
         }
 
         this.bar(a0);
     }
-    bar(a0: Partial<T>){
+    bar(a0: Partial<Class7>){
         this.mmeb = 3;
         this.foo(a0);
     }
@@ -88,14 +88,14 @@ class Class6<T> {
 class Class7 { fld: Number = 6;}
 
 class Class8 <T extends Class7> {
-    baz(a0: Partial<T>){
+    baz(a0: Partial<Class7>){
         a0.fld = undefined;
     }
 }
 
 function test_4(): void {
     let class7_partial: Partial<Class7> = {fld: 8};
-    let class6_original: Class6<Class7> = new Class6<Class7>();
+    let class6_original: Class6 = new Class6();
     class6_original.foo(class7_partial);
 }
 
diff --git a/ets2panda/test/test-lists/declgenets2ts/ets-runtime/declgen-ets2ts-runtime-ignored.txt b/ets2panda/test/test-lists/declgenets2ts/ets-runtime/declgen-ets2ts-runtime-ignored.txt
index 8b450fcd32da9b696f82c8e45cd6044cb86663ba..91e2b0af730ae0cd8eb48da252d759b2eda18c8d 100644
--- a/ets2panda/test/test-lists/declgenets2ts/ets-runtime/declgen-ets2ts-runtime-ignored.txt
+++ b/ets2panda/test/test-lists/declgenets2ts/ets-runtime/declgen-ets2ts-runtime-ignored.txt
@@ -25,7 +25,7 @@ as_string.ets
 function_type_with_receiver/extensionFunctionType_return_this.ets
 defaultExportObjectLiteral_exp.ets
 forOfCustomIterator3.ets
-too_many_async.ets
+fuzz/too_many_async.ets
 typeAlias_2.ets
 Multiline_string.ets
 Multiline_string_escape_char.ets
diff --git a/ets2panda/test/test-lists/srcdumper/srcdumper-ets-ignored.txt b/ets2panda/test/test-lists/srcdumper/srcdumper-ets-ignored.txt
index 536ae48707c490a5d7ffc56799c13324dd0af4af..1244e4746e4557a6495a8339013dfc432075abd0 100644
--- a/ets2panda/test/test-lists/srcdumper/srcdumper-ets-ignored.txt
+++ b/ets2panda/test/test-lists/srcdumper/srcdumper-ets-ignored.txt
@@ -40,12 +40,6 @@ runtime/ets/type_param_in_union.ets
 runtime/ets/StringFasta.ets
 runtime/ets/struct-identifier.ets
 runtime/ets/struct-init2.ets
-runtime/ets/too_many_call_expr.ets
-runtime/ets/too_many_async.ets
-runtime/ets/too_many_await.ets
-runtime/ets/too_many_left_brace.ets
-runtime/ets/too_many_left_square_brackets.ets
-runtime/ets/too_many_new_expr.ets
 runtime/ets/too_many_minus.ets
 runtime/ets/too_many_plus.ets
 runtime/ets/too_many_plus_1.ets
@@ -53,6 +47,11 @@ runtime/ets/too_many_tilde.ets
 runtime/ets/too_many_exclamation_mark.ets
 runtime/ets/fuzz/too_many_call_expr.ets
 runtime/ets/too_many_token.ets
+runtime/ets/fuzz/too_many_async.ets
+runtime/ets/fuzz/too_many_await.ets
+runtime/ets/fuzz/too_many_left_brace.ets
+runtime/ets/fuzz/too_many_left_square_brackets.ets
+runtime/ets/fuzz/too_many_new_expr.ets
 ast/compiler/ets/DeclareIndexerTest.ets
 ast/parser/ets/import_tests/import_class_with_static_field/import_class_with_static_field.ets
 
diff --git a/ets2panda/util/diagnostic/semantic.yaml b/ets2panda/util/diagnostic/semantic.yaml
index d117696b1bb01e1ee75770cd571cc637b92b9fe7..59ae05f94042fbdb281d9ddce60f26883f8beac7 100644
--- a/ets2panda/util/diagnostic/semantic.yaml
+++ b/ets2panda/util/diagnostic/semantic.yaml
@@ -976,6 +976,10 @@ semantic:
   id: 123
   message: "Spread argument for the rest parameter can be only one."
 
+- name: MUST_BE_CLASS_INTERFACE_TYPE
+  id: 124644
+  message: "T in {}<T> must be a class or an interface type."
+
 - name: NAMESPACE_AS_TYPE
   id: 158
   message: "Namespace '{}' cannot be used as a type."