if the above does not fix the problem - look into your T3 (CRA)/RL-16 (QC) forms; I had the same issue and the problem was that there were several separate T3/RL-16 uploaded to the CRA site by my investment advisor, then what originally looked like a summary (adding all entries) was a SEPARATE and DUPLICATE T3/RL16 form but with some of the fields missing. After confirming that the last T3/RL16 entry was indeed an error, I deleted the duplicate T3/RL16 and everything worked. Just filed QC. Good luck.
