This seems correct - the functions are named inconsistent with their behaviour ("set" in name but return a value) so this slipped by. You would want to open GMLive_std.gml in a text/code editor, find the following bit
#define __lnc__f1632
if (live_enabled) {
tile_set_empty(argument[0]);
} #define __lnc__f1633
if (live_enabled) {
tile_set_index(argument[0],argument[1]);
} #define __lnc__f1634
if (live_enabled) {
tile_set_flip(argument[0],argument[1]);
} #define __lnc__f1635
if (live_enabled) {
tile_set_mirror(argument[0],argument[1]);
} #define __lnc__f1636
if (live_enabled) {
tile_set_rotate(argument[0],argument[1]);
}
and change all of these to be "return tile_...();" .. "} else return 0;"
I'll change this for the next release.