I have "users" and "posts" collections i added a two ways relationships attribute , after that i removed the collection "posts", and now i can create a new user and i cant delete the relationship attribute when i try i got this error "Collection with the requested ID could not be found."
TL;DR
The user added a two-way relationship attribute between the "users" and "posts" collections. They then removed the "posts" collection, but now they are unable to delete the relationship attribute. They receive an error saying "Collection with the requested ID could not be found." A potential solution or workaround is not provided in the support thread.