there is nothing wrong with your T3.  I am having the same problem.  Box21 is total capital gains.  Box 52 and 53 need to add up to Box 21.  Its a error in the software where box21 is not being transferred to the corresponding line 68140. 

There is another post on this but no fix from Intuit.

I have a filled in box 21 but nothing in the footnotes about box 52 and 53.  I don't know if this is a t3 issue, a cra issue or a TurboTax issue.  All I know is I have a t3 issue on a tax law that didn't go through so this should be a non issue.  Make 52 + 53 = 21!!! And ignore period 1 and 2

Can you please confirm if you imported your T3 with our AFR? If yes, can you please go on your CRA My Account and verify your T3 to make sure that each box on your T3 was entered when imported?

I did not download the T3.  All entries done manually.

Box 21 on the T3 for 2024 is just the sum of the amounts in boxes 52 & 53. You need to put whatever is in Box 21 in either 52 or 53 for it to transfer to Schedule 3. It doesn't matter which as they are both taxed at the 50% rate, but for some reason using just Box 53 seems to work better for some people.

if you put the whole amount in box 53, it is still increasing the capital gains amount that they are claiming on their returns.  Can we bypass entering anything in box 52 or 53?  

I have downloaded the update and continue to have an error message.  My 52 and 53 do add up to 21, i have quadruple checked,  but software issue continues. 

The tax deadline is quickly approaching.....

@mystic_chika 

They said the error in the software will be fixed on April 14th.