How can I find out what is causing it in a confusing java file?

java.lang.RuntimeException: Missing type parameter.
    at com.google.gson.reflect.TypeToken.getSuperclassTypeParameter(TypeToken.java:84)
    at com.google.gson.reflect.TypeToken.<init>(TypeToken.java:62)
    at a.a.b.a.c.<init>(Unknown Source)
    at a.a.b.a.b.a(Unknown Source)
    at a.a.b.a.b.deserialize(Unknown Source)
    at com.google.gson.TreeTypeAdapter.read(TreeTypeAdapter.java:58)
    at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$1.read(ReflectiveTypeAdapterFactory.java:93)
    at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$Adapter.read(ReflectiveTypeAdapterFactory.java:172)`
    at com.google.gson.Gson.fromJson(Gson.java:795)
    at com.google.gson.Gson.fromJson(Gson.java:761)
    at com.google.gson.Gson.fromJson(Gson.java:710)
    at com.google.gson.Gson.fromJson(Gson.java:682)
    at a.a.b.d.d.b(Unknown Source)
    at a.a.b.i.run(Unknown Source)
    at java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source)
    at java.util.concurrent.FutureTask.run(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
    at java.lang.Thread.run(Unknown Source)

      

        
        
        
      

    

What's the StackTrace for the Java file I'm running (Obfuscated), I don't get this when my program is not obfuscated and running. So I concluded that this is caused by an obfuscator (ProGuard).

Is there a way to fix this or get some information on what might be causing this?