In the Search window, On searching different asset like 'Physics', Inspector can't be enabled because it doesn't exist an error is thrown in console. Refer attached video and stack trace.

Steps to repro:
1. Create a new project
2. Window > Search
3. Type any required asset name in Search (ex. Physics).
4. Observe the error in the console

Actual Result:
Error is thrown in console on searching different asset in the Search window

Expected Result:
The search window should show respective assets without throwing any error.

Occurring on:
2021.2.0a5, 2021.2.0a4

Working Fine:
2021.2.0a3, 2021.1.0b7

Note:
Quick Search is a Built-In Package in the Unity 2021.1.0a1

Environment:
Occurring on macOS 10.15.

Stack Trace:
Menu Assets/Create/Playables/Playable Asset C# Script can't be enabled because it doesn't exist
UnityEngine.GUIUtility:ProcessEvent (int,intptr,bool&)