ModuleNotFoundError: No module named '__main__.vtt'; '__main__' is not a package

[MM2018]

I think it works only with MacOSX!
Tested on latest ubuntu using virtualbox!
I am getting same error like windows

yl@yl-VirtualBox:~$ videogrep -i /media -s "Rule" -st word -o test.mp4
[!] No subtitle files were found.
Traceback (most recent call last):
  File "/home/yl/.local/bin/videogrep", line 5, in <module>
    videogrep.main()
  File "/home/yl/.local/lib/python2.7/site-packages/videogrep/videogrep.py", line 528, in main
    videogrep(args.inputfile, args.outputfile, args.search, args.searchtype, args.maxclips, args.padding, args.demo, args.randomize, args.sync, args.use_transcript, args.use_vtt, args.export_clips)
  File "/home/yl/.local/lib/python2.7/site-packages/videogrep/videogrep.py", line 456, in videogrep
    composition = compose_from_srts(srts, search, searchtype)
  File "/home/yl/.local/lib/python2.7/site-packages/videogrep/videogrep.py", line 317, in compose_from_srts
    for srt in srts:
TypeError: 'bool' object is not iterable
yl@yl-VirtualBox:~$ 

I tried on different file(added .srt file same folder), same error!