RT 4.0.15 is now available.
This release fixes an important regression in the ugprade scripts included in 4.0.14. If you attempted to upgrade from 3.8 with the RT FAQ Manager tables (FM_*) in your database, one of the upgrade scripts would error out.
If you were planning to upgrade from 3.8 using 4.0.14, please use 4.0.15 instead. If you have already upgraded to 4.0.14, there is no functional change in 4.0.15.
A permanent changelog is available.