No value has been specified for property 'classes'

when I try to ./gradlew build, I receive this error:

Task :jdactionMain FAILED

FAILURE: Build failed with an exception.

  • What went wrong:
    A problem was found with the configuration of task ‘:jdactionMain’ (type ‘NoActionVerificationTask’).

No value has been specified for property ‘classes’.

I searched this error everywhere but fould nothing. Help me, please!