I often use SQL Server Agent master / target servers (MSX/TSX). I find it so convenient to create the job once and then just add whatever targetservers (TSX) should have this job. Especially when you later modify the job. Again, just modify it once. The usage of MSX in general, and how I use it, can easily become a series of blog posts in itself. But that is not the point here.
Sometimes a TSX goes out-of-sync with its master. I've never understood exactly under what circumstances, but it feels like it happened when you do things "too quickly". Like change a job, push it out, and before the push has finished, you change it again. Or something like that. A TSX going out-of-sync doesn't happen frequently. I've had it a handful of times. And every time, I have spent time searching etc. on how to fix it.
A couple of days ago, a client of mine had this case, and he had himself tracked down a possible way to fix this. We decided to go ahead with this, and it worked just fine. So, the purpose here is to document the (very easy) fix, for whenever this happens again. And for all of you out there who might benefit, of course. The error you see is something like:
 An unresolved problem exists with the download instructions (sysdownloadlist) for target server 'Y' at MSX 'X'
X here is obviously the master and Y the target. And the solution was quite simply (in the msdb database):
EXEC dbo.sp_resync_targetserver, N'Y'
Are you using MSX/TSX? Have you had sync issues? How did you handle them?