I don’t know either, hopefully someone is able to test and report, I’m busy with other work atm.
I’ve never seen anything like this. Sounds like the engine is not able to find a properly compiled version of the FlyTo class.
Is this a blueprint-only project or C++? Have you installed the plugin as a project-level plugin or engine-level plugin? Your simplest option would be to remove the plugin and copy it again (either from the the sample project or directly from the plugin zip file). In case we’re dealing with corrupted files of some sort, try downloading the plugin and/or sample-project again.