Please dont say i have to start my song from scratch.    So.... i recorded a song, mixed it..saved it. Fine.   Tonight i saw a listing on TAXI which really suited my song and it has to be in by tomorrow. So i went to open the song just to check it sounded ok.  I got dll errors saying SD2 couldn't be found.  I recently upgraded to X3 so I'm actually using SD3 now. But the project opens and all instruments play fine....but no drums.  Oh great.  The meter (on the drums track) is moving up and down but it's like its on mute.  I usually do a "save as" when i'm recording a song in case something goes wrong. So i opened one of the earlier versions of the song and the same issue arose with the drums.       I did a rescan of the VST folder and it seemed to find all the plug ins but still no sound from the drums.    Now here's the weird part.  I opened a different song and the drums are fine.   So the problem seems to be with the song and not with the DAW.  I opened the inspector and checked the input / output settings of the working song and made sure the "faulty" song has the same settings but no joy.   If i open Session Drummer, as in, open the window which shows the drum kit, and hit a drum or cymbal, you can see cymbal moving but no sound.  I dont have the drums going to a bus by the way so it's not a case of the bus being muted. 
Please tell me someone has seen this before and I dont have re-do the song from scratch :(    Thanks guys. 

Try this first.
 
1) Install X3E if you haven't.
2) Try a RESET followed by a rescan of VST plugins (not just a rescan):
http://www.cakewalk.com/Support/Knowledge-Base/2007013315/SONAR-X3-Full-VST-Rescan-Recommended-for-Upgraders
 
Cheers..
 
 

After you get that sorted out, you might find this article useful about how to merge the SD2 content from previous Sonar versions with SD3.

thanks guys.  Alex, sorry for the dumb question but what is X3E   The next version of X3? 

X3e is the latest update and I highly recommend installing it. Alex would too.
 
http://forum.cakewalk.com...vailable-m3009206.aspx

Ah...thanks fellas.  Appreciate the help.

I know this is silly, but is there a kit loaded into the drums? Did you try loading a different kit. I had issues when I upgraded ( 8.5 to X3)  where my old pre sets had to be re made from scratch. 

I think sockmonkey hit it. Make sure a kit is loaded. It could have been overlooked.

Hi lads.  No you're not being silly at all Sock and in fact you would think that this is the problem...but the dang kit is loaded.  I have the songs backed up so if i have to reload Sonar then so be it.
Just an extra little bit of info guys.  I thought that all other songs were working.  I was wrong.  One song is fine the others all have the same problem.   The song that works is my latest song.  I cant say for certain...but...here is what i think is happening.      My latest song used Session drummer 3 and its working fine.   The others were recorded before i upgraded so they would have been done on SD2.    One of the guys put up a post further up on this discussion on merging SD2 with SD3.   I'll give that a shot and see how it goes.   At this stage, I guess i should be trying to get all my songs to use SD3.         

I dimly recall having a couple of instances where I had a midi track with data that was properly playing, and then for some reason, they no longer produced sound from their associated audio tracks.
 
Even MORE dimly, I think I ended up pasting the midi data into a new midi track, and also created a new audio track too, and then things were playing fine after that.
 
I never knew WHY the issues were there in the first place, and haven't had that kind of thing happen since.
 
Perhaps you could try something like what I posted above, to see if that helps you out.  Just a shot - but easy enough to try.  :)
 
Bob Bone