I had a similar issue with tt404 this is not a turbot ax file, and I did not transfer any file from 2016. Hope this help.
Here is what we did to solve my issue. Uninstall turbo tax software, update java, update window. Install c++2015. Delete my original turbo tax file. Re-boot computer. Re-install software. Start a new file. Thank you customer service for all your help. It work in my case, there is an update coming soon to fix this tt404 error.
Installed on Jan 9, 2018 and created a 2017 file. Everything was fine at that time. Today I opened quicktax and installed the latest update and it won't open my file, with the TT404 error. I have re-installed quicktax and installed all windows 10 updates, problem persists.
There is an error on installation with the microsoft redistributable, but was told it was ok to ignore.
Will there be a fix for this or do I have to start from scratch???????????????????????????
There was an update on Feb 2, If that did not solve your issue, you should call customer service.
The update caused the problem. I called customer service and they said to wait for the next update.