I click on the "+" to open a new tab but nothing happens.
Firefox opens in the home page but won't go to any other page from that tab so I've tried to open another tab but again nothing happens.
Alle antwurden (2)
hello, please update firefox & your plugins to the latest version.
in case this doesn't address the problem, then please see if you can replicate this behaviour when you launch firefox in safe mode once as well - if not, maybe an addon is interfering here...
Troubleshoot extensions, themes and hardware acceleration issues to solve common Firefox problems
Is that home page the built-in about:home page?
It is possible that your firewall or other security software blocks or restricts Firefox or the plugin-container process without informing you, possibly after detecting changes (update) to the Firefox program.
Remove all rules for Firefox and the plugin-container from the permissions list in the firewall and let your firewall ask again for permission to get full, unrestricted, access to install for Firefox and the plugin-container process and the updater process.
See:
Boot the computer in Windows Safe Mode with network support (press F8 on the boot screen) as a test.