I am using TurboTax online and during the Federal review I got the same message concerning the W-2c. This is a software issue with TurboTax. I am surprised that it wasn't corrected. When I reported it to TurboTax support last year, they advised me to ignore it and that it wouldn't affect my filing.
I reported this issue today to TurboTax and told them I was surprised this issue hasn't been address since last year!
I am also retired and get a W-2 from former employer for imputed income.
If you haven't, I recommend reporting it to TurboTax support. Maybe they will fix it.
