MtoA 184.108.40.206 is a hotfix release, that uses Arnold 220.127.116.11. It is fully binary compatible with 4.0.* versions.
mtoa#4304 Standins UI: regression in parameter overrides
mtoa#4273 Maya Standard Surface: Some Arnold Attributes are located in "Extra Attributes" in AE
mtoa#3988 Slashes in string attributes cleared on .ass import
mtoa#4288 [TX Manager] file node textures with sequences only converts first image
mtoa#4285 [TX Manager] error with tx manager with mtoaconstant* attributes
mtoa#4293 [TX Manager] Does not recognise maps with relative paths
mtoa#4289 Error with bifrostGraphShape at startup
mtoa#4297 Fix regression in standins contents selection
mtoa#4301 Error message in ProceduralWidgets.py
For more information go to visit Arnold Renderer Website.