Can't create AST mutations

Hello, I have tried MDroid+, but the mutations that created are all TEXTual.

I have not changed the property file, and in the execution log they are all exist.

Here is the apk that I tried:https://github.com/ChinaLHR/JianDou

And this is the log that MDroids create the mutations:mutation-create-log.txt

I tried it in both linux(ubuntu 16.04) and windows 10, but the creature are same.

Firstly, I think maybe there are some problems in the language?

However, I alse tried some English apps, such as:https://github.com/pockethub/PocketHub

The log is here:mutation-create-log2.txt

I found that there are some same exceptions that appeared in the log.

Which is: [SEVERE: Runtime Exception while casting TypeDeclaration].

And I think maybe it is the reason why AST mutations can't be created.

But I didn't find any information that can solve this execution.

Could you give me some advice?