After dealing with this issue for I can't remember how long, I finally got it sorted out. Problem was indeed due to a bad plugin. I booted in Safe Mode, added ".bak" to all installed plugins to rename them, and then rebooted. System rebooted without a problem and I readded my "neccessary" plugins one at a time. My problem was caused by an old version of "Nut" that I failed to uninstall. Installed the now recommended version and all is well! I LOVE Unraid!