I'm sure you are still debugging but I got this error.
ERROR in
action number 1
of Step Event
for object oCamera:
Error in code at line 1:
x1 = global.pid[1].x
^
at position 20: Unknown variable x
ERROR in
action number 1
of Step Event
for object oCamera:
Error in code at line 1:
x1 = global.pid[1].x
^
at position 20: Unknown variable x