Just leave it here
In my case (UE 4.27) the error is appeared for blueprint had a variable the parent C++ class with the changed type than was at the moment of creating blueprint.
To resolve are two ways:
- Is the complex way. Rename the C++ variable to temporary name and re-save the all blueprints derived from C++ class and ALL child blueprints. Then rename the C++ variable back and repeat re-save process of blueprints.
- Is the simple way. Just rename the C++ variable to new name differ from previous.
I used the second way
Possible the case of the topic is the same as my.
Need to rename the variable with ‘Arrow’ name of the parent C++ class of the ‘BP_Character Recorder’ blueprint