Through last Friday everything was running smooth on my self-built WHS 2011 server that has been running for a couple years. On Monday, I started having inexplicable errors, but only on certain things. I have always had my company file and hosted it on the server. Beginning Monday, I couldn't host the file or even access it across the network without massive, almost lockup, timing. Instead of 30 seconds or so to find, log in, and launch Quickbooks, it was taking like 10-15 minutes for each action. I found the same thing with the internal WHS 2011 programs (Backup restore, update, repair, etc.). Everything else works fine. I have a shipping program running on MSSQL without issue. I can access everything else (.pdf, .xlsx, .docx, images, videos, etc.) without any speed issue.
I am losing my mind trying to solve this. There hasn't been any updates to QB or WHS 2011 between last Friday and Monday. New updates this week don't solve the problem or seem to make it worse. The network is fine. The QB company file is fine; I moved it to a workstation to make every work again.
What else am I missing?