Access to file was denied.

If I use the “open with” option in certain directories, then LibO gives me the “access denied” message

This is some of the paths effected :
Access to /media/maritz/BA5E692A5E68E09D/Users/maritz/Documents/Templates/Fax Template.docx was denied.
Access to /media/maritz/BA5E692A5E68E09D/Users/maritz/Documents/VEHICLE MATTERS/Payment Calculator.ods was denied.
Access to /media/maritz/BA5E692A5E68E09D/Users/maritz/Documents/Security/Alarm Panel Table.xls was denied.

Paths not effected and opening files successfully are:
/home/maritz/Documents/
/home/maritz/Dropbox/

OS: Ubuntu 16.04 (snaps install)
Installed LO Version: 5.2.1.2
Build ID: libreoffice-5.2.1.2-snap1

Any idea what is the problem

Same problem here. Can’t access a file which is on my mounted drive.

Is /home/maritz/Documents/

referring to:

/media/maritz/BA5E692A5E68E09D/Users/maritz/Documents/ ?

Or are the other folders mounted drives? I am not sure how snaps are meant to work, but the idea is of course to isolate them from the system. Thus they may restrict access to mounted media.

I would also try to rename the files and folders and remove empty spaces (Fax Template.docx → FaxTemplate.docx) Maybe snaps have a problem to deal with those.
I would also post this question on AskUbuntu.com. Since snaps are a new Ubuntu technology, the people understanding your problem are much more likely to sit there.