I am using version 13.0.1. The page below has instructions on how to reset Firefox.
It says to go to "Troubleshooting Information" under the Help menu and that there will be a button to push called "Reset Firefox." But when I go to the Troubleshooting Information page there is no Reset Firefox button. I tried it on a few different computers and it is always the same.
Do you know where I can find it?
Yes it is due to you using the portable Firefox version.
For reading as to why as Bugzilla is not a discussion forum.