Hi, I detect crashes with some skeleton functions like: "skeleton_attachment_exists". 

I have seen that in the GMLiveAPI script file, the functions are defined as: "func=:(var)!:", On the other hand, for the "skeleton_attachment_exists" function the definition is: "skeleton_attachment_exists=(name)!:". I have modified this one by adding a colon after the equal like this: "skeleton_attachment_exists=:(name)!:"

I don't know if this is the solution, or if there are other functions that have this problem, but it has worked for me so far.

Your workaround is correct - the syntax inside GMLiveAPI for functions is

func_name=call_flags (arguments) return_flags

Depending on what the functions do, call_flags can be : (call with self), :: (call with self and other), or ::: (call with self and other, or just self if other is a nonexistent instance ID).

I get arguments from fnames file in the runtime directory, but flags are set by hand so it’s not very hard to overlook something.