Firebase: Reduce the number of distinct registered text parameters (in name, type) defined in your project to 20 - firebase

Question

We have some exciting new features coming soon to Google Analytics for Firebase, but we’ve noticed some issues with your project’s configuration which will prevent us from making those features available to you.
Our records indicate that you have a Firebase project (****513) that will be affected.
In the past, we’ve enforced configuration limits independently on each of the apps in your Firebase project. However, going forward, these limits will be enforced on a project-wide basis. As such, we need your help in making the necessary and appropriate changes to your project’s configuration to pave the way for access to our coming upgrades.
Specifically, we need you to make the following changes by April 25, 2018:
Reduce the number of distinct registered text parameters (in name, type) defined in your project to 20.
What's the number of distinct registered text parameters? because Firebase just gives 10 text parameter quota per app!

Answer 1

So what I undrestand from searching that reporting is moving from app-level to project-level, as they said In the past, we’ve enforced configuration limits independently on each of the apps in your Firebase project. However, going forward, these limits will be enforced on a project-wide basis. - this means that they all share the same user properties: for example, lets say "favorite_item" is a user property on 2 apps, then it would just be a single user property at the project level.
Listed here are the configurations which will be based project-wide:
Audience: 50 *Audiences which are identical in name (case-sensitive) and definition across every app will be counted as 1.
User Property: 25 *firebase_last_notification is included. *User properties which are identical in name (case-sensitive) across every app will be counted as 1.
Custom Parameters: 10 text and 40 numeric *For reporting only. 25 custom parameters per event for logging still applies. *Projects with 20 registered parameters or fewer are going to be ‘grandfathered’, they will be allowed to keep them. However, they won't be able to register new parameters.
Conversion events: 10 *Custom events only. Pre-defined events are not included.
A response from Firebase Support to Denny Huang
Thanks for reaching out to us. We have sent that email to all customers who are exceeding
limits for future enhancements to the product.
If you got an email for exceeding custom parameters in your project, this means the project
(combined all apps) has more than 10 distinct text parameters and/or more than 40 distinct
numeric parameters. It the project exceeds 20 distinct text parameters, you must unregister
extraneous text parameters to get below 20. Otherwise, if the project already exceeds the
limit of 10 distinct text parameters, no changes are required at this time, but the limit of 10 will
be applied when you attempt to register new parameters.

Answer 2

I got the same message, the problem was I had too many parameter reporting.
Every event has 3 dots on the right side to "edit parameter reporting". Remove few of those to get to max 20 across all project.

Answer 3

In logEvent documentation google documentation you can read:
Logs an app event. The event can have up to 25 parameters. Events with the same name must have the same parameters. Up to 500 event names are supported. Using predefined FirebaseAnalytics.Event and/or FirebaseAnalytics.Param is recommended for optimal reporting.
Also you have a limit on user properties:
If your app needs to collect additional data, you can set up to 25 different Analytics User Properties in your app. Note that user property names are case-sensitive and that setting two user properties whose names differ only in case results in two distinct user properties being logged.
it seems that you are logging an event with more than 20 different texts in the event parameters in all your apps