Importing Standard Assets from Asset Store in Editor throws error in console

Steps to Reproduce :

1. Create a new project
2. Import Standard Assets from Asset Store

Actual Result:
Errors in the Console

Expected Result:
There should not be any error after importing assets.

Reproducible on:
2018.3.0a9, 2018.2.0f2, 2018.1.0f1, 2018.1.0a4

Working Fine on:
2017.4.0f1, 2018.1.0a1, 2018.1.0a3

Environment:
Windows 10 and Mac 10.13

Stack Trace:
PlayerSettings Validation: Requested build target group (20) doesn't exist; #define symbols for scripting won't be added.
UnityEditor.PlayerSettings:SetScriptingDefineSymbolsForGroup(BuildTargetGroup, String)
UnityStandardAssets.CrossPlatformInput.Inspector.CrossPlatformInitialize:SetEnabled(String, Boolean, Boolean) (at Assets/Standard Assets/Editor/CrossPlatformInput/CrossPlatformInputInitialize.cs:127)
UnityStandardAssets.CrossPlatformInput.Inspector.CrossPlatformInitialize:.cctor() (at Assets/Standard Assets/Editor/CrossPlatformInput/CrossPlatformInputInitialize.cs:22)
UnityEditor.EditorAssemblies:ProcessInitializeOnLoadAttributes()

PlayerSettings Validation: Requested build target group (17) doesn't exist; #define symbols for scripting won't be added.
UnityEditor.PlayerSettings:SetScriptingDefineSymbolsForGroup(BuildTargetGroup, String)
UnityStandardAssets.CrossPlatformInput.Inspector.CrossPlatformInitialize:SetEnabled(String, Boolean, Boolean) (at Assets/Standard Assets/Editor/CrossPlatformInput/CrossPlatformInputInitialize.cs:127)
UnityStandardAssets.CrossPlatformInput.Inspector.CrossPlatformInitialize:.cctor() (at Assets/Standard Assets/Editor/CrossPlatformInput/CrossPlatformInputInitialize.cs:22)
UnityEditor.EditorAssemblies:ProcessInitializeOnLoadAttributes()