Open in new tab not working properly. How can I get it to stop opening new windows?

Question

Firefox recently updated and my + open new tab button was gone. I found and downloaded the extension to put it back on, which is now gone but never worked. I have checked options>tabs and it is supposed to be opening new tabs. I can click file open new tab and it still opens everything in a new window. I've loved firefox for several years but if this isn't fixable quickly I'm gone. Can anyone help?

Answer 1

You definitely should not need an extension to get a new tab button!
Do you have any tab related extensions now, such as Tab Mix Plus or Tab Utilities?
Try resetting your toolbar layout by renaming the file that stores customizations. Firefox should returns to the default settings for toolbars and windows. Here's how:
(1) Open your personal settings (AKA Firefox profile) folder
Help (or Alt+h) > Troubleshooting Information > "Show Folder" button
(2) Switch back to Firefox and exit the program (e.g., File > Exit)
(3) Wait a few moments for Firefox to finish updating files in your settings folder, then rename '''localstore.rdf''' to something else, like localstore-bad.rdf or localstore.old. Alternately, you can delete the file.
(4) You're done with your profile folder and you can restart Firefox now.
Any luck?
With respect to links launching in new windows instead of tabs, the checkbox in the Options dialog should work but there is an exception for scripted windows that have certain parameters set (e.g., dialog style with no toolbars, or a specific size). Launching a link out of a dialog, which is not allowed to have extra tabs in the window, also will launch either a new window or be added to an existing window. Any chance the problem is related to those situations?