HUGE lesson learned that may save another user a lot of time and pain: NEVER do a disc compression of your entire hard drive (commonly done to free up memory on your computer). 3D can't interact with the data files and SQL services it needs if they are compressed. We did a complete hard drive disc compression and lost all 3D functionality, until we discovered the problem. Once we decompressed all the files that 3D needed, everything returned to normal with no loss of data. If you're running out of memory, it's okay to do a disc clean-up, just don't do a disc compression. 3D Tech Support spent 3 hours trying to fix the problem on Friday to no avail. It took my brilliant brother to find the problem and fix it. Why 3D didn't know this is beyond me!