Trying to get the map movement working

I’ve added the code and a demo level to my code to test, but am having problems with it.

The error I get is:

Runtime error
…z07_0x4fkl00000gn/T/TemporaryItems/10/lime-utils.lua:254: attempt to perform arithmetic on field ‘x’ (a nil value)
stack traceback:
[C]: ?
…z07_0x4fkl00000gn/T/TemporaryItems/10/lime-utils.lua:254: in function ‘screenToWorldPosition’
…x7j56vz07_0x4fkl00000gn/T/TemporaryItems/10/game.lua:28: in function <…x7j56vz07_0x4fkl00000gn>
?: in function <?:215> [import]uid: 10389 topic_id: 21063 reply_id: 321063[/import] </…x7j56vz07_0x4fkl00000gn>