If you try and log into your project and you receive the error notification stating "Invalid CMS User", it normally means one of 2 things:
Your project users' unique ID (uid) does not match with one that we have on our records
Your project users' UID does not match with an entry within your database
flamelink/usersfor the Firebase Realtime DB orfl_usersfor Cloud Firestore. Also, be sure that the user has theenabledproperty set to"Yes"
This is a security feature, but we have found that the UID's can get out of sync if you remove and recreate your project user from within the Firebase console or when you switch sign-in methods. For instance, you use email/password for your user to log into your project within Flamelink and then use Google sign-in in your app. When not explicitly handled within your app code, the UID of your user can change if the email was not explicitly verified before, which will cause this error.
We recommend using Google auth for project logins within Flamelink. Using Google auth for Flamelink should mitigate this problem.
If none of this solve your problem, please send us your project ID along with your UID, so that we can compare it to the one we have on record. You can find this in the Firebase console.