You may need to clear your internet browser cache and cookies to clear this error. Doing this from time to time helps generate new forms and minimizes display issues on different websites.
Here are steps describing how to do this for Chrome. Please contact Tech Support if you are using another browser and need help finding the cache history.
After clearing cache and cookies, you should be able to log in to the Learning Portal. If you still have any issues, please contact Tech Support.
Collaborative Classroom Tech Support can be reached at firstname.lastname@example.org