Thanks lots for the solution!

Cheers,

Hey turbotax I'm having the same issue ,efiled my return a couple of weeks ago got 4 more T3s may 8th, entered and tried to refile but getting the same error message about boxes 52 and 53 adding to box 21 redid the math at least a dozen times and even tried the fix of putting the total in box 53 only and also rounding up the amounts no luck. It says print and mail return or try later. Is this turbotax issue or CRA.

Signed frustrated. 

Add me also to the list re boxes 52 and 53.

@Rickandkimp Remove the amount from Box 52, if applicable (leave it blank) - Enter the sum of Box 52 + Box 53 in Box 53 - Ensure Box 53 equals the amount in Box 21 If the error persists, try rounding the box amounts (21 and 53) to the nearest dollar. 

The new capital gains rate is not going into effect this year, so both boxes are taxed at the same one-half (50%) rate.