Thanks Walori!
You´re right: this particular error message disappeared when i included acknex.h, and just to be sure, i also included default.c too (just like in the workshops).
To be double sure, i COPIED the acknex.h and default.c scripts to my game folder, and shall do so to all included scripts inside those.
Problem is: those standard scripts have their own handles and predefined variable names, and i´m worried that sudddenly including them in my code may override or crash with my own variables and pointers... well, tought luck. I´m already receiving different error messages each run because of this wdl/lite-c transition, so it will be a while until i´ll be able to ACTUALLY run the game and see some runtime bugs again.
Thanks once again, dude.