If anyone is still willing to help, I would appreciate it:
https://crash.limetech.org/h6pa34otumc7
It seems to be happening on other peoples servers as well (says the crash report has happened over 730 times). I've tried removing almost all my plugins, extensions. Still crashes. Tried switching out SM versions from 1.8 to 1.9 back to 1.8. Not sure if anyone has any experience with this.