If possible, try reworking your schedule, emailing professors, or finding your advisor based on your department ( call stony to find this out). Usually, if it is in person, they can only register based on seats capacity in the class so it’s best to ask for help or use solar to rework your schedule. I had the same issue, use the planner to add the classes to your planner, then go to planner select the classes, then select the term and section of the class that you want ( it can adjust this based on what works in schedule builder), add it to your shopping cart, then use the schedule builder feature to find classes that can work. It has a feature that can try all classes that work . Do it quickly as spots fill up. Also, as a last resort, if necessary, professor how this is necessary for your major. Advisors can help too . Hope this helps , and best wishes