That error message occurs when the user or a script performed by the user attempts an action that the security settings do not allow. Using a full access account would then not trip this error. You'll need to figure out what action is triggering this error.
Best guess is that you have a script set in File Options to run automatically when the file opens. If this script has an action (could be as simple as go to layout) prohibited by the account security settings, you'll get this error message every time you open the file unless you use a password with full access.
The fix might be as simple as selecting the "run with full access privileges" option for this script.