Hello,

I'm sorry to hear that you're experiencing an issue with Firefox not reopening tabs after closing the browser. As a support forum contributor, I'd be happy to help you with this.

Based on the information you provided, it seems like you have the "Open previous windows and tabs" option enabled in Firefox's startup settings, which is the correct setting to restore your tabs when reopening the browser.

If closing Firefox using the hamburger menu (three lines in the top right) or the hotkey (Ctrl + Shift + Q) successfully reopens your windows and tabs, but closing it using the "X" in the top right corner doesn't, there might be a specific scenario causing this behavior.

To assist you further, I would recommend trying the following steps:

Clear your browser cache: Go to the "Options" or "Preferences" menu, then navigate to the "Privacy & Security" section. Under the "Cookies and Site Data" section, click on the "Clear Data" button and select "Cached Web Content." Restart Firefox and see if the issue persists.

Disable extensions: Some extensions can interfere with the normal functioning of Firefox. Try disabling all your extensions and restart Firefox to see if the tabs reopen correctly. If they do, you can enable your extensions one by one to identify the problematic one.

Create a new Firefox profile: Sometimes, issues can be related to the user profile. You can create a new profile and see if the problem occurs there as well. To create a new profile, follow the instructions in this Mozilla support article: Create a new Firefox profile.

If none of these steps resolve the issue, please provide more details about any specific circumstances or patterns you've noticed when the tabs fail to reopen. This information will help us further investigate and troubleshoot the problem.

Once you've tried the suggested steps or provided additional information, please let me know, and I'll be happy to assist you further with a reply on the support forum.

Best regards, Suram Mozilla Support Forum Volunteer

If you use the close X then you only close this specific window and normally only the last closed window would be restored. If you can have multiple windows open then you should use Exit/Quit (Ctrl+Shift+Q) in the File menu or the "3-bar" Firefox menu button, otherwise you can check "History -> Recently Closed Windows/Tabs" that allows to reopen three closed windows.

If you use the close X then you only close this specific window and normally only the last closed window would be restored.

Yeah, typically I keep all my tabs in one window, so the behavior I'm describing happens when I am closing one window containing 3-6 tabs.

If you can have multiple windows open then you should use Exit/Quit (Ctrl+Shift+Q) in the File menu or the "3-bar" Firefox menu button, otherwise you can check "History -> Recently Closed Windows/Tabs" that allows to reopen three closed windows.

I've been using this to recover the windows I last had open, but I'd love to just have them immediately available again.

If none of these steps resolve the issue, please provide more details about any specific circumstances or patterns you've noticed when the tabs fail to reopen. This information will help us further investigate and troubleshoot the problem. Once you've tried the suggested steps or provided additional information, please let me know, and I'll be happy to assist you further with a reply on the support forum.

I've tried all these basic steps before posting, but to your credit I didn't mention that. The problem seems to be more specific to the save-state of closing Firefox using the red "X" button in the top corner.

One other detail I just now noticed happened:

1. I closed Firefox using the "X", and for unrelated reasons, rebooted 2. When Windows came back up, I clicked the "Firefox" icon on my taskbar to launch it 3. Firefox briefly flashed up, a pure white window, but then closed 4. I waited a few seconds, then clicked the "Firefox" icon on my taskbar again 5. Firefox launched and presented me with a single new tab, none of the ones I had opened before

Is there a way to enable debug logging, perhaps something is being printed to `stdout` or `stderr` that could be a helpful clue?