I am also having this problem.
I don't know if it's a real change and I need to become an agency, (which I tried to navigate and couldn't) or if I just need to wait for it to be fixed.......hopefully they are working on it. All of the applications I am trying to submit revert to this message box. "You need to be an agency."
I'm kind of new at this and I was bearly getting into the groove. Then I read the forum and find out that the message system is delaying things like job messages or hire notifications. That might explain some of what I'm experiencing. One client hired me over the phone and I never heard from them again?? (and you're not supposed to call or bother them).
This is really frustrating I have plenty if connects left and try to only apply when I know I'm sutable for the project.