Seems this is a recent glitch ... I suggest waiting until Monday and try starting again and then every couple of days until it works. Or you can enter the assets again from scratch your choice.
The IRS will not start processing returns until 2/12 so you have time to wait.
If you have not paid for the online edition you are using, have not filed your tax return or registered the Free edition, then you can clear your return. Click on Tax Tools on the left side of the program screen while working on the 2020 online tax return. Click on Clear & Start Over.
