Twice a year on a set date MusicBrainz do a server release that includes changes to their schema database. Changes to the database can be disruptive for MusicBrainz customers who keep their own copy of the database whicc is why these changes are limited to two releases a year.
MusicBrainz did such a release on October 14th, the major change is that the concept of places have been added so that venues and recording studios can be added to the database. For example once the data is added you could see what albums have recorded at a particular studio. Maybe some of this information will be used by taggers at some point, but until a music player exists that can use this information I don't see much point.
If you are using the MusicBrainz VM with Jaikoz or SongKong I would advise a little patience, within the week there should be a new VM updated to the latest database and search, this is easier than trying to update the server yourself.
The new MusicBrainz server temporarily broke tagging with SongKong and Jaikoz, it exposed a bug in both applications and I quickly released new versions of SongKong (1.11.0) and Jaikoz (5.7.0) to resolve this issue. The change has temporarily been reverted to allow the earlier versions of SongKong and Jaikoz to function but will be added back in 1 months time so please get on and update your versions to the latest version.