Warning when Editing a Variable with an empty Gameplay Tag Query - Warning: Error parsing FGameplayTagQuery!

Warning is thrown when Editing an empty Gameplay Tag Query variable:

Warning: Error parsing FGameplayTagQuery!

This issue is also occurring in 4.21.2.

Once the Gameplay Tag Query has tags in the Query, this warning no longer occurs when Edit... is clicked.

Steps:

1. Open QAGame in UE4Editor
2. Make sure Output log is open and visible

   Window > Developer Tools > Output Log

3. Open BP_TagQuery
4. Create a New Variable
5. Set it's type to: Gameplay Tag Query
6. Compile the Blueprint
7. In the Details panel for this variable Click Edit

Results: Warning occurs in the log