The question is as the title suggests.

The environment is Xamarin.Forms in Visual Studio 2019 on Windows.

The error is not occurring in another project, and I think it's a bad NuGet included in the project...

The difference between a project that generates an error and one that does not is that you may or may not have updated the NuGet package when you started the project.

The NuGet packages included in the project that generate the error are as follows
-Xamarin.Firebase.Auth v121.0.1.1
-Xamarin.Firebase.iOS.Auth v6.9.2
-Xamarin.Firebase.iOS.CloudMessaging v4.7.1
-Xamarin.Firebase.iOS.Storage v3.9.1
-Xamarin.Firebase.Messaging v122.0.0
-Xamarin.Firebase.Storage v120.0

The NuGet packages included in the project that do not generate errors are as follows
-FirebaseAdmin v2.1.0

I haven't tried most of the methods that seem to be effective, so perhaps any advice would be helpful.

I only tried the procedure to rebuild after deleting the bin and obj folders in all folders.

I'm sorry to bother you, but I'm looking forward to your answer and thank you in advance.

CodePudding user response：

I found the problem, an error that appeared when updating to this link source, and tried to downgrade to test it.

Xamarin.Firebase.Storage v120.0.0 version to v119.2.2, the corresponding error no longer occurs.

That's all.