Good news: looks like TurboTax Online has been updated to fix this issue! I was just able to e-file. If you already told TurboTax you're going to file by mail, ...

In this case, deferral is just a fancy word for contribution.

I got this error when I tried to e-file my federal return. Apparently the workaround is to file by mail. As long as the excess deferral is the only problem the ...