Download new update and hey presto TB crashes everytime you open it! Have checked and rechecked everything and then all the advice on Community and Online. Solution is simple, once you know where to go! TB upgrade adds "Lightning" - TB's calendar feature whther you want it or not. As soon as you try to open an email from someone using Outlook and with a calendar appointment, TB crashes around your ears. Solution: 1. Open TB in Safe Mode. 2. Got to Tools : Add-ons : Extensions 3. Disable or Remove Lightning 4. Reboot 5. Your TB should be back to normal!