MAUI Multi-Program Architecture - Plugin Firebase not installed

Thank you for reaching out . Based on the error details this is a known iOS build issue related to Firebase iOS native frameworks and Swift module generation, not an Android or MAUI architecture issue.

Recommended Resolution Steps:

Step 1: Ensure Correct Firebase iOS Packages

make sure you have explicitly installed the iOS firebase packages, not only Android.
if your iOS project(.csproj):

<ItemGroup>
<PackageReference Include="Plugin.Firebase.Crashlytics" Version="3.0.0"/>
<PackageReference Include="Plugin.Firebase.Core" Version="3.0.0" />
</ItemGroup>

Installing only plugin.Firebase at shared level is not sufficient for iOS.

Step 2: Clean Nuget Cache (Critical)

Corrupted or partial NuGet restores cause this exact error:

Run the following on both Windows and Mac build host:

dotnet nuget locals all --clear

Then delete:

• bin
• obj
• ~/.nuget/packages/adame.firebase.ios.core

Step 3: Update Xcode & Command Line tools

Firebase iOS SDK requires a compatible Xcode version.

On the Mac:

xcode-select --install
sudo xcode-select --switch /Applications/Xcode.app

Ensure:

• Xcode 14.1 or later
• iOS SDK 16+

Step 4: Rebuild for Device (Not Simulator)

This issue often occurs only on Simulator builds due to missing slices.

Test on a physical iOS device:

dotnet build -t:Run -f net8.0-ios

if it works on device, this confirms a simulator only limitation.

Step 5: Disable Bitcode (if Enabled)

In your iOS project:

<PropertyGroup>
<MtouchEnabledBitcode>false</MtouchEnabledBitcode>
</PropertyGroup>

Firebase does not support Bitcode.

Step 6: Initialize Firebase Correctly in MAUI

Ensure Firebase is initialized only once in MauiProgram.cs:

builder
	.UseFirebaseApp()
	.UseFirebaseCrashlytics();

Avoid duplicate initialization across multiple projects in multi-program architecture.

Reference:

• https://quic.hkg1.meaqua.org/en-us/dotnet/maui/ios/deployment/?view=net-maui-10.0
• https://github.com/TobiasBuchholz/Plugin.Firebase

Please let us know if you require any further assistance we’re happy to help. If you found this information useful, kindly mark this as "Accept Answer".