A small-but-essential update to the IDE for stopping a start-up crash you may have seen in the release from last week whenever licensing had failed.
Now, if there is an issue with incomplete/stale licensing information in your user manager file, GameMaker will detect this and clear the file out, allowing you to start the program safely and log in again with no problems.
There are no runtime changes/no new runtime to download, so it's still version 152.
For the full info on this IDE update, see:
IDE Notes