Can not open header files

Tell me why can this happen?
Occurs in all C ++ files, in the plugin GameplayAbilities

Version UE - 4.20.2

update:

I forgot to say that there are no problems with the compilation. The problem is only with navigation by code.

In version 4.19, this problem was not.

It is possibly it is not included in your Game.Build.cs file. Try

PublicDependencyModuleNames.AddRange(new string[] {
 "GameplayTasks",       
 "GameplayTags",       
 "GameplayAbilities"
});

Adding it there would equivalent to adding a bulk of headers.

Did not help.

I forgot to say that there are no problems with the compilation. The problem is only with navigation by code.

In version 4.19, this problem was not.

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