"Permission denied" when reading xps files in Ubuntu 20.04 using evince
evince is the PDF viewer that ships with Ubuntu by default. It can open the following formats: PDF, Postscript, djvu, tiff, dvi, XPS, SyncTex support with gedit, comics books (cbr,cbz,cb7 and cbt).
If there's a "Permission Denied" error message when opening a file, then there's a good chance that you are attempting to do so from a symlinked folder. There are apparmor fixes out there to allow opening via a symlink, but I prefer to simply relocate the file to a non-symlinked folder like /home or /tmp.
The reason I had this error is that my Desktop folder is a symlink from another physical drive.
Temporarily copying the file to /tmp to open it solved the problem for me.