Latest ios 18 and vs updates killed maui build for iOS project

Question

I was using on older version of iOS and xcode to get some changes in before the cutoff date for supporting the older xamarin sdks.

I have been working on another maui app, which was building fine previously.

After udpating to the new mac OS and Xcode on the mac, and updating VS 2022 on my PC, I am no longer able to build the maui app for the simulators, it does work for an actual device.

The error I get is:

clang++ exited with code 1:

Undefined symbols for architecture arm64:

"_xamarin_is_object_valid", referenced from:

  <initial-undefines>

"_xamarin_is_user_type", referenced from:

  <initial-undefines>

ld: symbol(s) not found for architecture arm64

clang++: error: linker command failed with exit code 1 (use -v to see invocation)

Do I need to remove building for a certain architecture? I need it to run on older versions of iOS, at least back to iOS 12 or so.

The xamarin logs are not showing anything.

This is a .net 8 iOS project.

I always seem to run into issues when updating to the latest versions of everything. :(

Answer 1

apple recently (in April) required Xcode 16 for code signing, dropping support for earlier versions. While the Maui 8 had an updated workload to support Xcode 16 & ios18, Maui .net 8 is out of support, (ended May 14, 2025). You should upgrade to Maui .net 9