My wallet 1.2.4 is also stuck @ 250169. I had that problem right after the update, so I deleted the burst_db folder and let it redownload the whole blockchain. Now it's stuck again :|
Some users have stability issues with the core version 1.2.4. We are working on a solution and release a fix as soon as possible.
The core version 1.2.3 still works and will work after Block 255000 but the Blockchain has to be synced all over again unfortunately.