UPDATE: This is now fixed in v23.2.1 of the Itch app!

In case anyone on Windows is receiving the follow error message when launching RPG in a Box from the Itch app, there is a known issue with the latest version.

An error occurred while launching RPG in a Box

There should hopefully be a fix for this soon. In the meantime, you can click "Show local files" on the right-hand side and launch "rpginabox.exe" from the installation folder.