Object reference not set to an instance of an object when import Mob img

[brilam]

Hi,

I dumped a Mob image (such as 0100100.img) from v90 and I was trying to import it back to v83. However, when I do so I get the following error:

The file "C:\Nexon\v90\MapleStory\v90 Mob IMG\0100100.img" is invalid and will be skipped. Error: Object reference not set to an instance of an object.

[Arnuh]

Likely cause of the List.wz encryption