{"statusCode":400,"error":"Bad Request","message":"\"uid\" is not allowed","validation":{"source":"query","keys":["uid"]}}
e.g. https://id.webmaker.org/login?client_id=wm_id_wMvw9BSwq2A480...
If you try to login just from https://id.webmaker.org/login you will get the error you saw.
e.g. https://id.webmaker.org/login?client_id=wm_id_wMvw9BSwq2A480...
If you try to login just from https://id.webmaker.org/login you will get the error you saw.