Modpack version
1.55 Beta

Can the issue be reproduced?
Yes, on the specified version. Will attempt to reproduce on 1.56.

Logs
https://paste.ee/p/rP2Oo

Should be the correct crash log.

Issue
If a portable fluid ME drive is put in a ME Chest and a Extra Utilities 2 pipe imports a fluid NOT in the drive and the drive has space for the fluid, game hard crashes. On reloading the world, game locks up. World can be repaired by using McEdit and removing the entity data for the ME Chest but the player will lose the fluid drive and it's contents.

I had a drive with BioGas and Lava, an ME Chest with the drive in it, an accidental attachment of my EU2 pipe with running water, and had a hard crash after 3 seconds. Reloading the world would start loading blocks onto the screen but would freeze when loading the ME drive/EU2 pipe area. Work around fix is to remove the entity data using MCEdit.

If this is a feature request, feel free to delete the template.

Confirmed on 1.56. Issue is the ME chest itself. Putting the Portable fluid Drive in the Disk Drive rack thing doesn’t cause the issue.

Issue occures when ANY fluid stored in the cell is exported directly (via fluid conduit to the ME chest) or via Fluid export bus. Tested with biogas, water, and lava.

Stacktrace says it's a StackOverflow, so probably some sort of infinite recursion somewhere. Reporting this to the EC tracker.

EDIT: It's a known issue (ExtraCells/ExtraCells2#610), has been fixed in a dev version, there's unfortunately nothing more we can do about this other than wait for the updated build to be released on CF or hope that CF accepts the CI build of ExtraCells.