Try running it in safe mode (help -> restart with add-ons disabled) to see if its due to one of the add-ons. If that works, try unchecking checking for add-on updates in tools -> options -> advanced -> updates and restart Thunderbird normally. If that workaround the problem it might be easiest to just live with checking for add-on updates disabled for a while. Version 60 will probably be released within one to two months, and is expected to cause lots of issues for add-on compatibility .
Try specifying the profiles location using a command line argument per
http://kb.mozillazine.org/Running_from_ ... hunderbird (ignore the title, you don't need a usb drive) . That will help identify if your problem was due to the profiles.ini file normally used to find the profiles location.
I'm skeptical the problem is due to what accounts are in your profile. If its not due to an add-on, my first thought would be a inter-operability problem due to some other software on your PC. Try temporarily disabling some of your anti-virus/security software, reducing the amount of software in your system tray, updating your graphics drivers etc. You could also try booting windows in "safe mode with networking enabled" and see if that works around the problem. If it does, that implies the problem really was one of your drivers/services or other software loaded when you normally boot windows. Norton and Mcafee have a reputation for causing problems. Codestuff Starter at
http://www.snapfiles.com/get/starter.html is one way to easily manage what software is automatically run on booting (it avoids the need to use the registry editor etc.).
I recently had a problem where my PC would not shut off the fan during sleep mode anymore. I checked windows update was current, updated all of my drivers using the device manager, double checked everything in the advanced power management sections was correct (disable hybrid sleep, wakeup timers, USB selective suspend etc.) The fix was to update the DELL update app, which had said all of my software (other than itself) was uptodate. That fixed the problem. I'm mentioning this as an example of how subtle software interactions can be.
See
http://kb.mozillazine.org/Go_back_to_an ... hunderbird if you want to try a older version of Thunderbird. You might also try the latest beta from
https://www.thunderbird.net/en-US/channel/ . You don't necessarily have to uninstall your existing version, you could do a custom setup using a different directory. It will use your existing profile.