Can't put contraptions in the storage boxes

[Jafesu]

Accidentally put a Minecart Contraption into a storage box, it crashed the server, and now causes EXTREME lag to the point of crashes and timeouts whenever i go near my storage.

I cannot find the contraption in the storage boxes to remove it, its not displaying

[Jafesu]

Where is the contents of the storage boxes stored? I am trying to find through MBTExplorer so i can just yoink it out of there to try to save the server