u/Teleform

I'm making my first game in Gamemaker, and I've been making some progress. But suddenly, I made a minor change that spit out this error message:

The Error Message (Object: one_artifact Key Event: Key Down - E at line 31: Assignment operator expected)

When I looked into it, it said that this message shows up when I have an undefined or incorrectly call for a variable or function. But I didn't change anything related to a function or variable, and can't find where Gamemaker seems to think I have.

The code where the error occurs, according to GM

Can some help explain what's going on, please? Thanks in advance.

For context, I was trying to code an object to follow behind the player (obj_player) when being "carried." The error appeared when programming the y-coordinate shifts.