I was really excited to create web apps in Zorin 18 (using the built in tool) but have been having an issue. I created an Outlook web app referencing the Firefox browser, but on launch receive the message:
This does not bode well. It means that the apt package has been replaced by the snap package from Firefox. If you are satisfied with the snap version and everything is working well, then it is fine. Otherwise, you can remove the snap package from Firefox and try to install the real .deb package.
Follow the instructions for Debian bookworm there.
This (I think) led to the solution. From the software store it turned out I had both .deb and snap versions of Firefox installed. Snap version removed and things appear to working as normal.
If I have any further issues, I'll uninstall and reinstall following this link; thank you.