I receive an error from TWX Proxy version 2.5.73 when creating new databases.
It is a windows pop up error message with the extremely detailed and helpful error message of "An error occurred while trying to create the database."

Windows 8.1 Pro, I've tried with UAC on and off.
Running as administrator and not.
Tried as different user accounts.
I've re-extracted the files from the zip archive, and re-downloaded the archive.
It doesn't happen every time but when it does it seems to happen until i do one or more of the above and pray to the gods of intergalactic commerce before it starts working again.

Does anyone have any insight or ideas on what I can do to resolve this? I would prefer not to spend an hour on this each time I want to create a database.

I believe this is caused by a file remaining from a previous game with the same name. TWX has had an issue in the past deleting some of the game files when a game is deleted, which in turns causes the problem you describe when recreating that same-named game. It may have been solved already, but I can't swear to without reviewing the latest build. I'll check and let you know.

I have a "Ritual" I go through when creating a new database in TWX. First I clean out any old game files before creating a new database. After creating the new database and getting all the settings the way I want it, I close TWX before actually connecting to a game. This saves all the settings I just made. Then I fire it up again and start playing, and it doesn't matter if TWX crashes when I eventually close it.

When changing from a TWX version to another you need to delete this file "TWXSetup.dat" from the root of TWX. Then restart and make a game following what Micro stated in the previous post.