Xamarin No valid iOS code signing keys found in keychain

Very often when you download app sample from the web for Xamarin iOS and attempt to run it on a iOS simulator, you might encounter the following error “No valid iOS code signing keys found in keychain.”

The simple solution to this error would be to open up the csproj file and look for

<PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|iPhoneSimulator' ">
 <CodesignEntitlements><strong><em>Entitlements.plist</em></strong></CodesignEntitlements>
</PropertyGroup>

Remove ‘Entitlements.plist’ from the code and that should resolve the error. The below is the end result that you should get.

<PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|iPhoneSimulator' ">
 <CodesignEntitlements></CodesignEntitlements>
</PropertyGroup>

For more details, refer here