So the person over in the FB group called support and they had her remove the 1040 module and reinstall it....so might be worth trying.  You wont lose any data.

Windows Add/Remove Programs, choose ProSeries 2021 and choose Uninstall, it will look like its going to uninstall the entire program, DONT PANIC! its not.  Once you choose Uninstall it will open a window that has choices of which part to uninstall, choose 1040 and let it do its thing.   

When its done, restart your computer.  Log back into ProSeries and then go to Update > Select and Download New Products and recheck the 1040 box in the bottom left corner and once that's done, see if you have better luck.