(I don't know how tags work, I assume that's a mod action? Github noob here. I probably wrongly deleted my original issue...but in the interim, I reproduced the error and describe it below.)

Issue description:

My first attempt at a Turbine multiblock. I unknowingly omitted the electromagnetic coil level, but made a 2 high rotor. I closed up the structure, saw red sparks flash for a multiblock complete, then the server crashed.

Steps to reproduce:

1. Build the following (incorrect) reactor, 5x5 base, (I followed the guide wrong and missed the coils, I made the rotor 2x high, whereas the wiki's minimum is obviously 1x high): L1 base, L2 rotor, L3 rotor, L4 rotational complex + 8 pressure distributors, L5 casing.
2. The electromagnetic coil level above the rot complex and distributors doesn't exist.
3. As soon as you complete the top casing, client and server crash.

Version (make sure you are on the latest version before reporting):

Forge: 1.15.2-31.1.50
Mekanism: 1.15.2-9.10.1.414
Other relevant version: Mekanism Generators 1.15.2-9.10.1.414

If a (crash)log is relevant for this issue, link it here: crash-2020-04-30_04.56.53-server.txt

Thanks for the detailed issue, but closing it as we are currently tracking this crash here: #6100 and it is fixed in dev.