Unable to load the "XamlCTask" task from the build"........."; failed to load the file or build "Xamarin.Forms.Build.Tasks»?

I sent my app by email to another person. when it launches the app, these errors come out. what could be the problem?enter image description here

first error:

the XamlCTask task was incorrectly declared, incorrectly used, or an error occurred during its build. Check the correct spelling of the task name for the build name

second error:

unable to load the XamlCTask task from the build "D:\Syst\Desktop\проект\winforms\packages\Xamarin.Forms.4.6.0.847.\build\net46\Xamarin.Forms.Build.Tasks.dll". Failed to load the file or build "Xamarin.Forms.Build.Tasks, Version=2.0.0.0, Culture=neutral, PublicKeyToken=798c2ba514f889d3" or one of their dependencies. This operation is not supported. (Exception from HRESULT: 0x80131515)