docdiff broken without user feedback

TortoiseHg 6.4.2 When trying to compare a docx document with the docdiff tool nothing happens.

When I call docdiff directly on the command line, an exception occurs:

"C:\Program Files\TortoiseHg\docdiff.exe" "Path to docx file" "Path to other docx file"
Traceback (most recent call last):
  File "docdiff.py", line 114, in <module>
  File "docdiff.py", line 105, in main
  File "mercurial\encoding.pyc", line 253, in unifromlocal
  File "mercurial\encoding.pyc", line 227, in fromlocal
TypeError: a bytes-like object is required, not 'list'

Question: Would it be possible that errors from docdiff are propagated to the UI, so that the user has a feedback that something went wrong?

I tried some older thg versions (that I had lying around locally). Here is the result:

5.9.3 OK
6.2.1 Exception
6.4.2 Exception

I also tried to change the codepage in the command window to "chcp 1252" before starting docdiff, but the error persisted. I did not change hgencoding!

Would be nice if this regression could be fixed. In the meantime I am restricted to use the 5.9.3 version when I want to compare Office documents.