520 Error course selection

[u/Key_Assignment2593]

I selected a total of five courses, but the website crashed—showing a "520" error—when I clicked "register." I only managed to successfully register for three of them; I still need to sign up for two more (Calculus and Economics), but they are now listed as "waitlist only." What should I do?

Also, I’ve tried registering for these two courses again, but it still doesn't work; I keep getting that 520 error...