The first time you log in to CloudStor, the identity provider (ie. your insitution's login) used is recorded against your username. If you attempt to login via a different identity provider the "Incorrect Identity Provider" error will be shown.
The intention behind this is to prevent fraudulent access to your account by restricting access to your account to your home institution.
If you do not believe you should be seeing this error, please contact your institution's help desk to confirm there has been no changes to the identity provider.