how to resolve "The sum of box 52 and box 53 cannot be negative and must equal the total capital gain or loss in box 21."

For all T3 slips in your return: - 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 and submit via NETFILE once more. 

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