404 error for loan consolidation

when I try to consolidate my loans, it gives me a 404 error. I only get it when I try to consolidate my Perkins loans with my other subsidized and /unsubsidized loans. I don’t get the error if I remove the Perkins loans from the list of loans I want to consolidate.

is anyone else having the same issue or know who to fix this? I received my perkins loans from my school and all the other loans from the same loan provider