If you have any self-employment income or a T4A with income in box 28 in the wrong place, it will upgrade you automatically. Standard version does not do the same things it did last year.
That could be a problem. From what I have seen on here, if you start a new return, it wants to start a new version of what you have got. You can start a new return under a new sign in, or try to start a different version to see if it will cooperate.
