Steps to replicate:
Place 2 fluix mana pools in same network, place sparks on both, make 1 recessive, attach storage bus to recessive pool, and import bus to other.
Connect a mana cell to the system, and input mana into the system.
In some versions, this requires setting the priority of the storage bus higher than the mana cell.
Afterwards, system will quickly use mana.
It seems when system stops seeing mana, this will lead to a crash.
Any time system is loaded afterwards, the game will crash.

Bug was first encountered on valhelsia 5, but replicated on latest version with minimal mod list.
Can be solved by disabling addon and reenabling thankfully.