APK to JAR & JAR to java
some error occure when using procyon-decompiler-0.5.26.jar
with the third project 
error example:
BAD TYPE ARGUMENTS: [TT;]; [null]
java.lang.IllegalArgumentException: Argument 'typeArguments' must not
have any null elements.
	at
com.strobel.core.VerifyArgument.noNullElementsAndNotEmpty(VerifyArgument.java:145)
	at
com.strobel.assembler.metadata.CoreMetadataFactory$UnresolvedType.makeGenericType(CoreMetadataFactory.java:566)
	at
com.strobel.assembler.metadata.CoreMetadataFactory.makeParameterizedType(CoreMetadataFactory.java:154)
	at
com.strobel.assembler.metadata.signatures.Reifier.visitClassTypeSignature(Reifier.java:125)
	at
com.strobel.assembler.metadata.signatures.ClassTypeSignature.accept(ClassTypeSignature.java:46)
	at
com.strobel.assembler.metadata.MetadataParser.parseClassSignature(MetadataParser.java:394)
	at
com.strobel.assembler.metadata.ClassFileReader.populateBaseTypes(ClassFileReader.java:665)
	at
com.strobel.assembler.metadata.ClassFileReader.readClass(ClassFileReader.java:438)
	at
com.strobel.assembler.metadata.ClassFileReader.readClass(ClassFileReader.java:366)
	at
com.strobel.assembler.metadata.MetadataSystem.resolveType(MetadataSystem.java:124)
	at
com.strobel.decompiler.NoRetryMetadataSystem.resolveType(DecompilerDriver.java:447)
	at
com.strobel.assembler.metadata.MetadataSystem.resolveCore(MetadataSystem.java:76)
	at
com.strobel.assembler.metadata.MetadataResolver.resolve(MetadataResolver.java:104)
	at
com.strobel.assembler.metadata.CoreMetadataFactory$UnresolvedType.resolve(CoreMetadataFactory.java:576)
	at
com.strobel.decompiler.languages.java.ast.AstBuilder.convertType(AstBuilder.java:274)
	at
com.strobel.decompiler.languages.java.ast.AstBuilder.convertType(AstBuilder.java:235)
	at
com.strobel.decompiler.languages.java.ast.AstBuilder.convertType(AstBuilder.java:153)
	at
com.strobel.decompiler.languages.java.ast.AstBuilder.convertType(AstBuilder.java:149)
	at
com.strobel.decompiler.languages.java.ast.AstBuilder.createMethod(AstBuilder.java:644)
	at
com.strobel.decompiler.languages.java.ast.AstBuilder.addTypeMembers(AstBuilder.java:532)
	at
com.strobel.decompiler.languages.java.ast.AstBuilder.createTypeCore(AstBuilder.java:499)
	at
com.strobel.decompiler.languages.java.ast.AstBuilder.createTypeNoCache(AstBuilder.java:141)
	at
com.strobel.decompiler.languages.java.ast.AstBuilder.createType(AstBuilder.java:130)
	at
com.strobel.decompiler.languages.java.ast.AstBuilder.addType(AstBuilder.java:105)
	at
com.strobel.decompiler.languages.java.JavaLanguage.buildAst(JavaLanguage.java:71)
	at
com.strobel.decompiler.languages.java.JavaLanguage.decompileType(JavaLanguage.java:59)
	at
com.strobel.decompiler.DecompilerDriver.decompileType(DecompilerDriver.java:304)
	at
com.strobel.decompiler.DecompilerDriver.decompileJar(DecompilerDriver.java:225)
	at
com.strobel.decompiler.DecompilerDriver.main(DecompilerDriver.java:110)