I am running LO on Kubuntu 20.04.
LO ver 6.4 uses a web browser to display help files (from local disk). According to what I can see from the documentation, LO uses for its browser whatever the system default browser is. Previous to upgrading Kubuntu to 20.04 (Focal) , my default browser was Chromium, and this worked as intended.
After upgrade to 20.04, however, Chromium was replaced by a “snap” version of Chromium, which runs in a sandbox and is prevented from reading local files. (Are you with me so far?).
In order to work around this, I changed the default system browser from Chromium to several other browsers (e.g. Firefox, Brave, etc.) and while this worked for the system, LO did not recognize the changes. Apparently, it sticks with whatever was the default browser when it was first installed, or something. It keeps using Chromium (snap) which “cannot find the file”.
Moreover, it seems that snap Chromium cannot be forced to change its behavior without changing the source code and rebuilding. (Not for me)
As a workaround, I edited the chromium.desktop file to point to the Brave browser instead, and this works. However it seems to me to be a rather unsatisfactory hack.
Hopefully, I am missing something about getting LO to change its default browser. Advice welcome!