Not able to decompile selected apk

Hi i have been facing this issue with the multiple apk which is in my local computer drives.
The parsing get started with below command in cmd

qark --apk my_app_path.apk

but after running for say 60-90 sec it not work and hangs completely.

and on aborting manually it gives
Error running fernflower
I have installed all the perquisite required for executing qark.
please help me for resolving this issue and proceed further.

Platform Windows 10 ,Python 2.7.13 pip is upgraded to 19.
In case you want anything please let me know.

After two days i got below error

Failed to extract fernflower jar with command 'jar xf app-release.jar'
Traceback (most recent call last):
  File "c:\python27\lib\site-packages\qark\decompiler\decompiler.py", line 294, in unpack_fernflower_jar
    retcode = subprocess.call(command)
  File "c:\python27\lib\subprocess.py", line 168, in call
    return Popen(*popenargs, **kwargs).wait()
  File "c:\python27\lib\subprocess.py", line 390, in __init__
    errread, errwrite)
  File "c:\python27\lib\subprocess.py", line 640, in _execute_child
    startupinfo)
WindowsError: [Error 2] The system cannot find the file specified

Start with the qark --apk invocation and the traceback in qark/decompiler/decompiler.py at line 294, where unpack_fernflower_jar runs jar xf app-release.jar. Reproduce the failure on the stated Windows and Python versions, then trace the Fernflower extraction command. Done means the cause is documented and APK decompilation either completes or reports a clear actionable error.