MissingPluginException(No implementation found)

[grisvladko]

Hello, as i've seen there is no particular explanation to why is it happening or what is the exact solution, but i will try because i'm stuck on that issue.
Project overview: we have an app that embed flutter as a module. everything works when not adding firebase_crashlytics.
Our module works if embedded as is into a clean iOS project, meaning that the problem is somewhere in iOS.
My guess is that there is a clash between dependencies, but i can't know for sure. what can you suggest to resolve that problem ?

Exception Trace:
MissingPluginException(No implementation found for method Firebase#initializeCore on channel plugins.flutter.io/firebase_core)
#0 MethodChannel._invokeMethod (package:flutter/src/services/platform_channel.dart:156:7)

#1 MethodChannel.invokeListMethod (package:flutter/src/services/platform_channel.dart:344:35)

#2 MethodChannelFirebase._initializeCore (package:firebase_core_platform_interface/src/method_channel/method_channel_firebase.dart:30:23)

#3 MethodChannelFirebase.initializeApp (package:firebase_core_platform_interface/src/method_channel/method_channel_firebase.dart:77:7)

#4 Firebase.initializeApp (package:firebase_core/src/firebase.dart:42:31)

#5 main (package:ProjectName/main.dart:267:3)