How can I view 2 tabs at the same time?
I would like to view 2 pages simultaneously. I have dual monitors and I cannot open a second window or start a second Firefox. The function under File/New window does not open a new window. Trying to start Fire fox a second time does not work. Unchceking "Open new window in a new tab under Tools/Options/Tabs " did not help.
Alla svar (1)
Start Firefox in Diagnose Firefox issues using Troubleshoot Mode to check if one of your add-ons is causing your problem (switch to the DEFAULT theme: Tools > Add-ons > Themes).
See Troubleshoot extensions, themes and hardware acceleration issues to solve common Firefox problems and Troubleshoot issues with plugins like Flash or Java to fix common Firefox problems
If it does work in Safe-mode then disable all your extensions and then try to find which is causing it by enabling one at a time until the problem reappears.
You can use "Disable all add-ons" on the Safe mode start window to disable all extensions.
You have to close and restart Firefox after each change via "File > Exit" (Mac: "Firefox > Quit"; Linux: "File > Quit")