Please update TurboTax. Here is what you can do if TurboTax can’t update itself: https://turbotax.community.intuit.ca/replies/3262510
If the .tt18 file still won’t open, locate the .ttbk file with the same name (in the same folder) and change the extension to .tt18. Then open that. By default, TurboTax puts files in a location that looks something like this: C:\Users\yourname\Documents\TurboTax\2018
Colleen S
New Member
xmiragex
Returning Member
anitaramdhani7-g
New Member
barb64
New Member
daniel-j-morton1
Level 1
You have clicked a link to a site outside of the TurboTax Community. By clicking "Continue", you will leave the Community and be taken to that site instead.