I have a similar issue. I installed 10.0.4.1 last week, on Win7(32-bit), and it ran fine. I came back this morning after the weekend, and now the lw.ttf file is missing. It was not missing before.
The question is, how would the file have been removed? There are no other users of this PC. Symantec Endpoint Protection is what's used for antivirus, the logs show no detection/quarantine/deletions.
Rebooting did nothing, as the file was missing. I uninstalled/reinstalled from the same installer file, and it now works fine again.
I made a backup copy of the lightworks program folder, and if this happens again I'm going to compare the two to see if there are more files missing than just the lw.ttf.