The Canada Revenue Agency (CRA) EFILE system is having issues with transmissions of amended T1134, T1135 and T106 returns. You may receive error code 485.
The CRA advises preparers to wait to transmit amended T1134, T1135 and T106 returns until this issue is resolved. This includes waiting to file these types of amended returns from all TaxCycle modules (T1, T2, etc.).
We are in communication with CRA and will update this news article once they resolve the issue.