Actually error code 603 apparently happens for no apparent reason. I just attempted to open my 2019 Turbotax and was informed I needed to enter the registration. When I did I got error code 603. I have it loaded on only 2 computers and it was registered on the computer it now is not working on. Apparently the registration can become corrupted. Now I have to find how to get Intuit to get this fixed. Comments here do not seem to cover when then registration count is corrupted.
