''<p>silcf [[#question-1429957|said]]</p>'' <blockquote>Thunderbird Tools menu has Run Filter on Folders and Delete Mail Marked as Junk greyed out. </blockquote> Thunderbird's menu is context sensitive so unless you see folders below all the mail type functions like run filters are disabled. <blockquote> 1. Several folders and their subfolders and emails have vanished. </blockquote> That can occur when the folder tree.json file has issues and deleting it from the profile folder with Thunderbird not running will often fix the issue. However in the case of IMAP accounts folder for account that are not accepting connections also disappear until they can be reinitialized from the servers canonical store. <blockquote> 2. None of the message filters that were working are working. Yes the fileres are enabled checked and "Run selected filter(s) on:" is set to the inbox connected to my email address. </blockquote> What does your filter log show when you select run now? <blockquote> 3. The Tools-> Run Filter on Folders is greyed out 4. The Tools-> Delete Mail Marked as Junk is greyed out </blockquote> See my initial comments <blockquyote> I have seached the web for help and I have looked for settings that may need to be checked or set but have found nothing that helped. </blockquote> The following is fairly normal standard diagnostic steps, other than the request for information. But if your situation is sort of randomly messed up it does sound like an antivirus toolbar might be behind the issues. They think they can write code for Thunderbird and force feed it, but it is rarely compatible for more than one version Could you please do the following? # Open the menu '''[[Image:Fx57Menu]] > Help > Troubleshooting Information''', then click '''Copy text to Clipboard'''. # Go to https://pastebin.mozilla.org/, paste the clipboard by right clicking in the large text area, select paste from the menu, change the retention period to expire in 28 days, use the '''Paste Snippet''' button to create a page containing your info, then copy the resulting URL (address) of the page created. # Open a reply to this post, and paste the URL to your troubleshooting information you just copied. # Please also provide results for the following test on your system #* Does Thunderbird work as expected in [[Troubleshoot Mode Thunderbird|Thunderbird troubleshooting mode]]? #* Does Thunderbird work as expected with your OS started in '''[http://en.wikipedia.org/wiki/Safe_mode safe mode with Networking]'''. Instructions for each operating system: [https://support.microsoft.com/en-us/windows/start-your-pc-in-safe-mode-in-windows-92c27cff-db89-8644-1ce4-b3e5e56fe234 Windows 10/11], [https://support.microsoft.com/en-us/windows/windows-startup-settings-including-safe-mode-7f31dcea-6427-0ba0-ec1b-729a56321cd3 Windows 8], [https://support.microsoft.com/en-us/windows/advanced-startup-options-including-safe-mode-b90e7808-80b5-a291-d4b8-1a1af602b617#start-computer-safe-mode=windows-7 Windows 7], [http://support.apple.com/kb/ht1564 OSX]

URL https://pastebin.mozilla.org/XtsbDhcs FYI: I also use Mawarebytes Premium 4.6.5 to periodically run a scan. I After going into troubleshooting mode and coming back out, filters are working as is the delete Junk. However, the missing folders are still missing.

''<p>silcf [[#answer-1615996|said]]</p>'' <blockquote> However, the missing folders are still missing. </blockquote> As you accounts are POP accounts, use the troubleshooting information to open the profile folder. Close Thunderbird In the file manager widow that opened to the profile folder content, locate and delete foldertree.json and restart Thunderbird. That files is essentially a cache of the tree of folders on the left. Deleting it forces Thunderbird to go look on the hard disk and find then all over again so it will slow the startup the first time. But it is usually a sure fire cure for those computer glitches that just make no sense.