Line 21 and lines 52 and 53 add up but turbo tax questions the amounts. why

Save yourself some grief.  Just switch to the "FORMS" mode and locate the T3 forms. On that panel you will see your T3 form(s) that you entered, 1 column for each T3, and then input the values you see on your T3 in the appropriate boxes. Once you're done you can go back to the Easy Steps mode and get past the error.

TurboTax has a bug where I found a value that I entered in Easy Steps mode did not show up on the actual T3 form.
Hope this helps.

Why has this software not been updated?

Thank you

Your solution worked like magic.  I was ready to tear my hair out!

You are welcome! 

I tried the fix recommended by Sparky 2025 and it worked and I could file with CRA.

I still get the error on April 29 when I try to netfile. 

Some of my T3's do not have any info in boxes 52 and 53, one has info in boxes 52 and 53.

Does anybody know how to fix this error?

I added in box 53 the value of box 21 even for the physical T3 slips that had no 52 or 53 value and that solved it for me

Another person suggested pulling up the Forms and getting g the T3 firm to fill in.  Delete whatever you have in easystep under t3 and enter it on forms then go back to easy step. It worked perfectly 

The easiest solution is to input the amounts of Box 52 and 53 on the T3 into the second set of boxes on the system - not in the Foreign income fields. They total the amount in Box 21 of the T slip and you are able to Netfile.