You can go over the return and see if anything you entered is related to the locked forms. Most of them are Capital Gains/Loss related.
Also, some people in Quebec are having problems filing if they have a T3 or T5 slip on their return. Our development them is working on resolving that issue.
If you are not using any of the locked forms Please try clearing the unneeded form and then closing unused forms. You can find those options under Edit>Forms in the top menu.
