Placed a Black Hole Unit in the End. Server crashed, client crashed. Was able to reboot server, since End wasn't loaded, another player was able to log in and continue where they were. Tried to log in with my client (the one that placed it), instant crash. I was only able to fix it by deleting my End folder and thus the offending block.

Industrial Foregoing Version: 1.12.2-1.9.0-163
TeslaCoreLib Version: 1.12.2-1.0.14
Crashlog (If Any):

server crash log: https://pastebin.com/qL5Ap46w
client crash log: https://pastebin.com/uHnzdDWh

Tried it in an RFTools dimension, same result.

Update to latest

thank you for the heads up/reply. I appreciate it