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Sometimes not all browser windows reopen when restarting Firefox

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A few days ago, I restarted Firefox because it was becoming too slow. When the browser reopened, one of the windows I try to keep open was gone. When I went to Recently Closed Windows, it was not there, so I began recreating the missing window. Today I restarted the browser, and when it restarted, the missing window reappeared. I had this same problem with one of the other windows 1 or 2 years ago, and never did recover the missing window. Is there a way to fix this, or keep it from happening again? I normally have 3 windows open, and have 159 tabs for window #1, 377 tabs for window #2, and 310 tabs for window #3. Is it safe to close the window I partially recreated?

A few days ago, I restarted Firefox because it was becoming too slow. When the browser reopened, one of the windows I try to keep open was gone. When I went to Recently Closed Windows, it was not there, so I began recreating the missing window. Today I restarted the browser, and when it restarted, the missing window reappeared. I had this same problem with one of the other windows 1 or 2 years ago, and never did recover the missing window. Is there a way to fix this, or keep it from happening again? I normally have 3 windows open, and have 159 tabs for window #1, 377 tabs for window #2, and 310 tabs for window #3. Is it safe to close the window I partially recreated?

All Replies (1)

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Over 800 tabs? I'm amazed that is even possible. But to answer your question, Firefox should not lose a window; even if a window is closed, the last three closed windows still should be re-openable. Since the window came back, I wonder whether there was some glitch that caused the window to be invisible when it was restored?? Since this occurs so infrequently, I don't really have any suggestions except to make backups of your profile folder.