Cant open local files

[mgsmath]

Describe the bug
the extension is unable to open any local files gives error url moz-extension://cac0e847-ede2-4459-84b5-990f2a20e7b7/help/stg-unsupported-url.html#file:///home/user/Desktop/School/zzhomw/home.html

To Reproduce
Steps to reproduce the behavior:

1. open local file eg. html pdf
2. put it into a group
3. close firefox
4. reopen firefox and go to that group
5. will give error message

Expected behavior
i expect it to open local files like it opens urls

Screenshots

Desktop (please complete the following information):
zorin os 17 based of ubuntu
extension version 5.2
Firefox version 134.0

[philg-dev]

This is a Firefox limitation / restriction for security reasons.

See also:
#811
#948