Update: Clearing both main directory cache and data cache allowed me to get on, but -not- anything regarding running in administrator or clearing one, trying, and the other.. Had to clear both before trying to get on.
Also for whatever it's worth, troubleshooted the same fix with Cerb, which did -not- fix it for him.
Also for whatever it's worth, troubleshooted the same fix with Cerb, which did -not- fix it for him.