This build, (1793), released on 13th October, 2015, is the second update to 2.50.x after the release of 2.50.0 Final on 21st December, 2012.
It is primarily a bugifx release, but it also introduced some UI improvements for ZQuest, and a few minor features.
The ZScript API specification did not change.
The internal version ID increased from 28 (2.50.1) to 30 (for 2.50.2).
ZC 2.50.2 DID NOT have a release candidate phase. it was rushed into a final build, and as a result, some issues that the userbase could have helpted to correct became a gigantic flaw in the release:
This build fixed the offsets for Screen->DrawBitmap(), so that it was automatically offset against the passive subscreen, which caused quite an uproad in the userbase, as older scripted quests that used DrawBitmap() broke, drawing at the wrong position.
This is most clearly demonstrated with 'Dark Room' scripts, as the overlay was drawn at -56 pixels from where it should appaer.
Because of this, ZoriaRPG created the header ZVersion.zh, to detect 2.50.0, 2.50.1, and 2.50.2 versions of ZC, and automate corrections for playing a quest in any of these three (main) releases.