App crashes when enabling proguard

[jkasnicki]

Repro steps: Set minifyEnabled to true

Expected behavior: App continues to work

Actual behavior: App crashes on startup with error like: com.google.firebase.database.d: No properties to serialize found on class com.google.firebase.codelab.friendlychat.a

com.google.firebase.codelab.friendlychat.a is the FriendlyMessage class.

Annotating that class w/ @Keep locally works. Something like https://github.com/firebase/quickstart-android/blob/master/database/app/proguard-rules.pro may also work.

[vegatroz]

I got this error too, and find someone's suggestion in this forum Just type below code to FriendlyMessage.java under Public Class FriendlyMessage : public FriendlyMessage() {}

It solved my problem

[imrankst1221]

In my case I forgot to add a proguard rule to keep the model classes:

-keep class com.google.firebase.example.fireeats.model.** { *; }