The first step to registration problem solving is to read all of the error messages. Oftentimes, you can problem solve on your own by reading the error messages.
Once you read the error message, please view the University Registrar's "Registration Add Errors" help page.
I can't register!
Registration Add Error Messages
Do you meet the requirements?
If you received a prerequisite or test score error and believe this is incorrect, this may be because of a prerequisite course substitution or a user error.
Is the class closed?
If a course you want to register for is closed, you may want to know what your next steps are.