Line 12C on Page 2 of my Form 1040-SR is blank. This is a total line.

The blank line 12c on Form 1040-SR is a bug. It has been reported to TurboTax.

You didn't say whether you are using TurboTax Online or the CD/Download TurboTax software. If you are using TurboTax Online there is nothing you can do except wait for TurboTax to fix the bug.

If you are using the CD/Download software, you can make it print Form 1040 instead of Form 1040-SR. Form 1040 will show the correct amount on line 12c. In forms mode, open the Federal Information Worksheet. Scroll down a little to Part II, where your address is shown. A few lines below your address is a line that says "Print Form 1040-SR instead of Form 1040." On that line, click the No box. Then it will print Form 1040.

Thanks!  I am using TurboTax download.  I will try your suggestion to print myself a copy.  My concern is if I electronically file the field will be blank and the IRS will have a problem.

If you leave it set to print Form 1040 I'm pretty sure the e-file will be okay. Another user who had the same problem used the Form 1040 option and e-filed without any problem.

Thanks for the help!  I will do that.

This worked.  Thank you!