Firefox Opens 3/4 Screen

[Jim2345]

Hello Yet Again,

My wife's Firefox always opens three quarters screen horizontally and has to be switched to full screen to be useable.

Even after updates, same 75% screen horizontally. This *can* happen, in Windows 10 at least, if the canvas-fingerprinting prevention measure is activated, but it isn't activated in this instance. That machine is running Windows 8.1.

Is this a known problem? Would a re-install fix it ? (Seem to remember I tried that).

---
Jim
PS I have to re-register with this forum each time I try to log in. My (correct) credentials are always rejected. I'm running out of believable email addresses.
On the odd occasion, I *can* sign in - such as just after re-registering ...

There's also a problem with the security question. As far as I can tell there are seven letters in 'Mozilla', not six !

[DanRaisch]

Nope, there are sixletters as the question should actually read "How many unique letters are there in the word Mozilla". Yes, that's not obvious but it's unlikely the question will be changed as the administrator has been absent for some time.

Do you have Firefox set to clear cookies and site data on closing? Check that under menu path Tools->Options->Privacy and Security.
Are you running any sort of clean up utility like Ccleaner on your computer?

As for the 3/4 screen issue, see this article. http://kb.mozillazine.org/Corrupt_localstore.rdf

[Jim2345]

Nope, there are sixletters as the question should actually read "How many unique letters are there in the word Mozilla". Yes, that's not obvious but it's unlikely the question will be changed as the administrator has been absent for some time.

Do you have Firefox set to clear cookies and site data on closing? Check that under menu path Tools->Options->Privacy and Security.
Are you running any sort of clean up utility like Ccleaner on your computer?

As for the 3/4 screen issue, see this article. http://kb.mozillazine.org/Corrupt_localstore.rdf

Thanks for your reply.

I was actually able to sign in with Bitwarden and didn't have to put the credentials in manually - oh joy !
I clear cookies on exit and use Bleachbit to clean.

I've looked at the link you gave and will try to work through it.

Thanks again.

Jim