Configurations: all 64 game configuration are now available by default.
Game Configurations window: game configurations can now be disabled. This setting is mostly cosmetic. When a game configuration is disabled, it won't be shown in "game configuration" dropdowns in New\Open Map Options and Map Options windows. If a map's .dbs file specifies a disabled configuration, it will be picked as a map configuration anyway.
Linedefs mode: vertex insert preview logic used Highlight range instead of Stitch range (which is used when draw mode engages).
Visual mode: double-sided middle textures were not selected when using "Select" action with "with same texture" modifier.
Textures: some optimizations in patch blending code.
ZDoom ACS script configuration: added definitions for StrLeft, StrMid and StrRight functions.
Things can now be cut, copied and pasted in Visual modes.
Sector geometry was not updated properly after Undo/Redo in GZDoom Visual mode.
Fixed an error when user selects multiple things and attempts to view their properties in Doom map format.
Added Decorate and Modeldef syntax hilighting, autocompletion and item recognition to Script editor.
Script Editor can now autodetect several script types when you open them (currently ACS, Decorate and Modeldef scripts are recognized).
Tag Explorer: fixed a bug when Tag Explorer update can block keyboard keys release detection logic.
Enhanced scripting workflow.
Thing and linedef arguments can now have default value in configuration files.
Fixed laggy visual camera movement on systems with big uptime.
Fixed incorrect alignment of Things with "hangs" flag in GZDoom Visual mode.
Fixed Editor crash when nodebuilder fails to build map. A window with error description will be shown instead.
Doom light levels were used even in maps in non-doom map format.
Tag Explorer plugin:
Elements list wasn't updated when map element was deleted.
Pugin wasn't disposed properly, which may led to Doom Builder 2 crash on map close.
Fixed plugin crash after opening another map.
Fixed unresponsive text entry in Filter text box.
Fixed plugin crash when Doom Builder can't determmine thing category ("UNKNOWN" category will be used instead).