Same problem. We need an answer.

Ok, I did some playing around with TurboTax and I think I figured it out. It has to do with how it calculates what deduction you should take. If you skip the calculations to determine if you should itemize, that seems to cause this error. If you go into the itemized/standard deduction calculator, it will ask you to enter all of the charities that you donated to for 2020. After I did that, it stopped giving me the error.

Normally I wouldn't enter any of the information about charities that I donated to, because I never reach the standard deduction amount. In this case, TurboTax doesn't tell you that you need to put them in, even if you do not itemize. And the error it gives you is very unhelpful, it doesn't say that it's checking the number you entered in for CARES Act donations against what you entered into the itemized list.

same problem and i need of a clear procedural steps to punch through this glitch

I found this response by one of their tax experts on another message board. I had the same issue and this really helped me:

"This is a known software issue.  The workaround is to delete the $300 in the error check. Then go back to Deductions & Credits and enter the contribution there, in the Donations to Charity topic. Then click Done with Donations and proceed through the screens until you get to the screen that tells you that TurboTax has added in the contribution.

The contribution will be back on Form 1040 line 10b, but it won't be flagged as an error. It only gets flagged if you enter it when prompted after you finish Deductions & Credits and the software tells you that you are getting the standard deduction. It will not get flagged if you enter it in Donations to Charity."

If the above steps did not work for you, here is another workaround:

1. Click Deductions and Credits
2. Select Review/Edit
3. Click Edit to the right of Standard Deduction ​​Click OK, Sounds Good
4. Click Wrap Up Tax Breaks
5. Click Continue
6. Make sure that $300 is filled in and then click Continue
7. Click Lets Keep Going

None of the "work around" steps I have seen so far on this site work for me.  I am itemizing deductions and continue to get a flag for line 10b when I do the Federal Review.  I am stumped at how to get around this so I can file my taxes.  Although the IRS extended the date to submit your taxes, this does not apply to state taxes.  I was thinking about just printing out my taxes since they are correct but cannot get through flag in Turbo Tax, and then mailing them instead of electronically as a solution.  This is very frustrating as I have been waiting for 2 months for a solution to this flag in Turbo Tax.

Two possibilities.  One, this TurboTax Help was just released.

Two, I am not sure whether you want to claim the deduction or remove the deduction.  If you are in TurboTax Online, the screen Charitable Cash Contributions under CARES Act appears as the end of Deductions & Credits. First you have to pass the screen Based on what you told us, the standard deduction is best for you at the end of Deductions & Credits.

But you have to qualify for the standard deduction before the screen appears.  So you may have to change the value of one or more itemized deductions to $1 so that you qualify for the standard deduction.  To remove the deduction, follow these steps: 

• At the top of the screen, click on Deductions & Credits.
• Scroll to the bottom of the page and click on Wrap up tax breaks.
• Continue through several screens.
• At the screen Based on what you told us, the standard deduction is best for you, click Continue.
• At the screen Any Charitable Cash Contributions? delete the dollar amount.
• Continue through Federal Review to make sure that things look correct.
• If you changed your itemized deductions, restore to the correct values and Review.