Check your .gdns file, make sure class_name correspond to the name of your class in C++ (if your nativescript is C++ of course, in any case the names must match)
Yes i have checked class_name matches to c++ class but still i am getting this error.
Plugin works perfectly but i always get this “Condition “!script_data” is true” error in editor
When I made a new class that I registered in GDNative I had the same Condition "!script_data" is true problem. I fixed it by just restarting the Godot Engine editor.