Xamarin.Forms System.ArgumentException: Illegal characters in path

Issue

I am brand new to Xamarin.Forms projects. I have created a project with VS2019 which has not been modified in any way, added a Pixel 2 Pie 9.0 - Api 28 emulator within the Android Device Manager. When I try to run the project on the android emulator, I am unable to run my app, with the following exception in my error list:

Error       XARDF7004: System.ArgumentException: Illegal characters in path.
   at System.Security.Permissions.FileIOPermission.EmulateFileIOPermissionChecks(String fullPath)
   at System.Security.Permissions.FileIOPermission.QuickDemand(FileIOPermissionAccess access, String fullPath, Boolean checkForDuplicates, Boolean needFullPath)
   at System.IO.Directory.Delete(String fullPath, String userPath, Boolean recursive, Boolean checkHost)
   at Xamarin.Android.Tasks.RemoveDirFixed.RunTask()
   at Xamarin.Android.Tasks.AndroidTask.Execute()   

Since I am simply using a basic project template generated by VS2019, this has to be a bug on Microsofts end. How can I fix their error?

Solution

It had to do with the character length of my solutions folder.

C:\Users\david\Dropbox\Projects\Visual Studio\PriceWatch\PriceWatch\PriceWatchXamarinForms\PriceWatchXamarinForms

(This bloated structure was generated by the IDE, everything after the Visual Studio folder)

I changed it to C:\Projects\PriceWatch\PriceWatchXamarinForms and then it worked.

Answered By - JohnWick