Crashlytics Piracy Checker java.lang.VerifyError

[yarik1988]

• [x ] I have verified there are no duplicate active or recent bugs, questions, or requests.
• [x ] I have verified that I am using the latest version of PiracyChecker.
• [x ] I have given my issue a non-generic title.
• [ x] I have read over the documentation (before asking questions on how to do something).

Details

• PiracyChecker version: 1.2.8
• Device OS version: 7.1.2
• Device Manufacturer: Samsung
• Device Name: Galaxy Note 10.1 2014 Edition

I got the error in Firebase Crashlytics:

Fatal Exception: java.lang.VerifyError: Verifier rejected class com.github.javiersantos.licensing.LibraryChecker: void com.github.javiersantos.licensing.LibraryChecker.onServiceConnected(android.content.ComponentName, android.os.IBinder): [0xFFFFFFFF] bad string index 65535 (max 44921) (declaration of 'com.github.javiersantos.licensing.LibraryChecker' appears in /data/app/com.magicart.waterpaint-1/base.apk)
       at com.github.javiersantos.piracychecker.PiracyChecker.verify(PiracyChecker.java:16)
       at com.example.myapplication.utils.CommonUtils.piracy_check(CommonUtils.java:16)

I have about 1000 active users, and this is the first error of such kind. I wonder whether it is error in the code or someone was trying to hack my app?