The scope of the update grew somewhat.
There was quite a bit more involved in the last update than a 'cheat item'.
It is possible to revert to the previous game version, but that would also require reverting to a save made before the last update.
With the GOG release, in Galaxy select the game, then the settings icon at the top right (beside the Play button) and under Manage Installation select 'Configure...', then uncheck automatic updates, in order to manually select the last update.
With Steam, it is possible to download previous versions of games using a console in the client. See
this guide and the
related screenshots.
Note that the guide suggests moving the current install folder and replacing it with the downloaded version, but it would be easier to leave the current install in place, and move the downloaded folder wherever you want to play from (perhaps renaming it 'DOS2 old version', or something), and start it from the executable until the next update.
After confirming the previous version works, you can delete the 'bin', 'Classic' and 'Data' folders from its main folder, since you don't need a duplicate of the original release of the game (just the 'DefEd' folder).
