Error CompileAppManifest Task Failed Unexpectedly

Hope you’ve had a lovely Easter! I caught the flu the week before, and am still recovering. Flu plus Easter = I was away for over a week. Which means by the time I came back and did a pull there had been quite a few changes in the work code base. After staring at the screen for two hours running various updates I finally got around to attempting a build, but got the following error:

Xamarin.Shared.targets(614,3): Error
MSB4018 : The "CompileAppManifest" task failed unexpectedly.
System.NullReferenceException: Object reference not set to an instance of an object.
   at Xamarin.MacDev.Tasks.CompileAppManifest.SetXcodeValues(PDictionary plist, IAppleSdk currentSDK) in /Users/builder/azdo/_work/1/s/macios/msbuild/Xamarin.MacDev.Tasks/Tasks/CompileAppManifest.cs:line 534
   at Xamarin.MacDev.Tasks.CompileAppManifest.Compile(PDictionary plist) in /Users/builder/azdo/_work/1/s/macios/msbuild/Xamarin.MacDev.Tasks/Tasks/CompileAppManifest.cs:line 338
   at Xamarin.MacDev.Tasks.CompileAppManifest.Execute() in /Users/builder/azdo/_work/1/s/macios/msbuild/Xamarin.MacDev.Tasks/Tasks/CompileAppManifest.cs:line 166
   at Microsoft.Build.BackEnd.TaskExecutionHost.Execute()
   at Microsoft.Build.BackEnd.TaskBuilder.ExecuteInstantiatedTask(TaskExecutionHost taskExecutionHost, TaskLoggingContext taskLoggingContext, TaskHost taskHost, ItemBucket bucket, TaskExecutionMode howToExecuteTask)

If you come across this, take a closer look at the error.

The null reference exception is in the SetXcodeValues method, which usually means you have a SDK mismatch. For me it was simply a missing workload update since I was updating my environment:

dotnet workload update

If you get this error, make sure you have the right Xcode version for the MAUI version you are using.

Hope this helps!

Error CompileAppManifest Task Failed Unexpectedly

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