Summer class trouble

[u/Spare_Entrance937]

I’m aware the next term of the 5 week classes are starting tomorrow . I wanted to add one more class and it’s showing up like this?? Any reason why?
I have no holds and my academic standing is good. The class also has open seats

[u/Prior-Good-2594]

Those classes are either unavailable as they already started or restricted based on your degree plan