This is an unplanned minor release containing some important bug fixes but no new features:
- reworked transaction handling - transactions are now opened only when necessary for write operations which improves concurrency and fixes some deadlocks in special situations
- frontend components were previously using exclusive locks but this caused some deadlocks in specific cases. These exclusive locks have been removed
There are other, small bugfixes as well.
If 0.42.X is working for you then there isn't much need to update to this release, but if you have problems, give this release a try.