Link to the readme: https://forums.dovetailgames.com/threads/public-beta-build-77-1a.80104/
Highlights: Addressed; Crash during alt tabbing. No stars at night with Silver Lining. Added some new developer tools. Improvements to cause of some OOM crashes.
Changes to Blueprint editor, updated to 64 bit and command lines ConvertToGeo, ConvertToTG and Serz. The information on this is in the first paragraph and you may need to provide pathing to your Railworks folder.
These are experimental and DTG is requesting feedback.