I had the same Error code 606 after installing TT deluxe from CD version purchased thru Amazon. After reading this thread I figured it was my Bitdefender causing the problem. I took jk11's advice and ran Windows Event Viewer (right click Windows starter icon; launch Event Viewer from drop down; click on "Windows Logs" then the "Application" tab). Sure enough there was an "Application Error" showing "Faulting module path:C:\Program Files\Bitdefender\". I did the following:
- completely uninstalled TT
- shut off Bitdefender Anti-Virus
- rebooted
- went into my TT account, entered my license code and downloaded TT Deluxe from the website
- installed the downloaded file
- rebooted
- launched TT -- FYI the banner still came up as Basic
- TT asked to update (which it didn't do in earlier attempts when Anti-Virus was active)
- after the update it asked for and accepted the license code and fully launched as the Deluxe version
After a few minutes, however, it did crash so I rebooted again (Anti-Virus was still off). When I opened the program after the reboot it completed another update including a "critical" program update from 1/21/20. Since then it's been stable even after turning Bitdefender back on. I hope this helps anyone else with the Error 606 issue...
