When playing Nomifactory CEU and using one set of (EnderStorage) ender chests, I experienced a random crash. Loading the world again, I experienced another crash. The error on the crash report reads:

net.minecraftforge.fml.common.LoaderExceptionModCrash: Caught exception from EnderStorage (enderstorage) -- 9 | Caused by: java.lang.RuntimeException: EnderStorage was unable to read it's data, please delete the 'EnderStorage' folder Here: [redacted name of the folder the world is in]\EnderStorage and start the server again. net.minecraftforge.fml.common.LoaderExceptionModCrash: Caught exception from EnderStorage (enderstorage) Caused by: java.lang.RuntimeException: EnderStorage was unable to read it's data, please delete the 'EnderStorage' folder Here: C[redacted name of the folder the world is in]\EnderStorage and start the server again.

The report goes on to say that the crash was caused by:

Caused by: java.util.zip.ZipException: Not in GZIP format

I made a backup, deleted the indicated folder, then loaded the world. There was no crash, but the ender-chest inventory was deleted. Why is this happening and what can I do to prevent future crashes?