The process cannot access the file because it is being used by another process: 'help_crack.res'

[industrialsociety]

Have 3 machines running help_crack.py and on one of them I am getting this intermittently. Only way to clear it is fully reboot the machine.

Traceback (most recent call last):
File "C:\Users\x\help_crack.py", line 938, in
hc.run()
File "C:\Users\x\help_crack.py", line 895, in run
os.unlink(self.conf['res_file'])
PermissionError: [WinError 32] The process cannot access the file because it is being used by another process: 'help_crack.res'
PS C:\Users\x\hashcat-6.2.3>