```
Error:cannot generate view binders com.sun.tools.javac.jvm.ClassReader$BadClassFile: bad class file: .../app/build/tmp/kapt/stageDebug/classFileStubs/.../common/view/EventsDelegatingWidget$DefaultImpls.class
    undeclared type variable: D
    Please remove or make sure it appears in the correct subdirectory of the classpath.
  	at com.sun.tools.javac.jvm.ClassReader.badClassFile(ClassReader.java:357)
  	at com.sun.tools.javac.jvm.ClassReader.findTypeVar(ClassReader.java:948)
  	at com.sun.tools.javac.jvm.ClassReader.sigToType(ClassReader.java:653)
  	at com.sun.tools.javac.jvm.ClassReader.sigToTypes(ClassReader.java:862)
  	at com.sun.tools.javac.jvm.ClassReader.classSigToType(ClassReader.java:778)
  	at com.sun.tools.javac.jvm.ClassReader.sigToType(ClassReader.java:691)
  	at com.sun.tools.javac.jvm.ClassReader.sigToTypes(ClassReader.java:862)
  	at com.sun.tools.javac.jvm.ClassReader.sigToType(ClassReader.java:716)
  	at com.sun.tools.javac.jvm.ClassReader.sigToType(ClassReader.java:639)
  	at com.sun.tools.javac.jvm.ClassReader.readType(ClassReader.java:562)
  	at com.sun.tools.javac.jvm.ClassReader$13.read(ClassReader.java:1158)
  	at com.sun.tools.javac.jvm.ClassReader.readAttrs(ClassReader.java:1381)
  	at com.sun.tools.javac.jvm.ClassReader.readMemberAttrs(ClassReader.java:1371)
  	at com.sun.tools.javac.jvm.ClassReader.readMethod(ClassReader.java:2044)
  	at com.sun.tools.javac.jvm.ClassReader.readClass(ClassReader.java:2252)
  	at com.sun.tools.javac.jvm.ClassReader.readClassFile(ClassReader.java:2324)
  	at com.sun.tools.javac.jvm.ClassReader.fillIn(ClassReader.java:2511)
  	at com.sun.tools.javac.jvm.ClassReader.complete(ClassReader.java:2442)
  	at com.sun.tools.javac.jvm.ClassReader.access$000(ClassReader.java:76)
  	at com.sun.tools.javac.jvm.ClassReader$1.complete(ClassReader.java:240)
```