"X3 lost Session Drummer 64"

Did it also lose Session Drummer 4 through 63?

I am having a similar problem only it's with Melodyne in X3 64 bit. The .dll is in the programs folder but the scan is not picking it up. Only VV is listed in the region FX. I followed the instructions above but it didn't help?

Make sure your download was not corrupted by antivirus software.  I had to temporarily disable Avast on my computer, as it was reporting false positive's during download, and other interference/corruption can occur, so it is best to just suspend your antivirus software prior to download.
 
Bob Bone
 

Well, I did finally get Session Drummer to work in X3, but not the way it was really supposed to.  I tried uninstalling X3 and X2 and then reinstalling X3 alone.  That didn't work.  I even tried deleting all Cakewalk registry entries after uninstalling.  No luck.  Then, after installing X3, I deleted the Session Drummer folder in my VSTplugins folder and installed X2 using the Advanced option and only added SessionDrummer64 as a plugin to install.  After doing that, SD64 works in both X2 and X3. 
 
I did notice that the SD64 dll that X3 installs is 1708 kb and the one X2 installs is 1568 kb.  Was there some kind of change in SD ?
 
I think robert may be right, maybe my download is corrupted.  I may try re downloading it, sometime.  But for now,  I have it working.
 

I have brought this to CW's attention.  Apparently their is no real concern about this.  ("A reinstall should fix the problem.")  There are a number of threads regarding this issue.  What I had to do to fix this, after attempting plug-in reinstall in hope of a fix, was to go into the registry and find the strings and such to make sure everything for the x86/32bit (under C:\Program Files (x86)\Cakewalk\Vstplugins and Shared DXi folders) plugs where matched for the counterpart x64 folders under C:\Program Files\Cakewalk\...  So, having both versions of VSTi's (x32 and x64 bit) creates a conflict in the registry.  This has also affected DXi's when having both SONAR x32 and x64 versions installed.  That is, not all DXi's would show up in the x64 version and were then missing in the x32 version (after x64 installation with x32 existing).  I was able to "pull them out" by fixing the registry, particularly Pentagon I (and VELOCITY), for example.
 
I don't believe we should have to noodle around the registry (or do complete uninstall and reinstall of SONAR) in order to fix this problem.  Surely this can be resolved with a fix to the installation process.
 
Kind regards,
 
Living Room Rocker
 
P.S.  This affects plug-ins randomly.  It does not necessarily happen to the same plugs for everyone.

Living Room Rocker
I have brought this to CW's attention.  Apparently their is no real concern about this.  ("A reinstall should fix the problem.")  There are a number of threads regarding this issue.  What I had to do to fix this, after attempting plug-in reinstall in hope of a fix, was to go into the registry and find the strings and such to make sure everything for the x86/32bit (under C:\Program Files (x86)\Cakewalk\Vstplugins and Shared DXi folders) plugs where matched for the counterpart x64 folders under C:\Program Files\Cakewalk\...  So, having both versions of VSTi's (x32 and x64 bit) creates a conflict in the registry.  This has also affected DXi's when having both SONAR x32 and x64 versions installed.  That is, not all DXi's would show up in the x64 version and were then missing in the x32 version (after x64 installation with x32 existing).  I was able to "pull them out" by fixing the registry, particularly Pentagon I (and VELOCITY), for example.
 
I don't believe we should have to noodle around the registry (or do complete uninstall and reinstall of SONAR) in order to fix this problem.  Surely this can be resolved with a fix to the installation process.
 
Kind regards,
 
Living Room Rocker
 
P.S.  This affects plug-ins randomly.  It does not necessarily happen to the same plugs for everyone.

Try the following:

• Hold CTRL+SHIFT
• Double-click on the icon for SONAR X3
• Select [OK] to personalize

All else fails, run the installer for SONAR X3 and when you are prompted for a Basic or Advanced install choose "Advanced".  Once you get to the list of the different features here make sure to un-tick everything and just tick Session Drummer 3.  Just SD3 will install. 

Hope this works!
-DG
 

I haven't yet tried the "Re-Install X2 option" and I'm not all that interested in registry hacks.
I'm seeing the same issue with Session Drummer after upgrading. I've reinstalled X3 several times. I've re-installed only selecting Session Drummer in advanced mode. 
 
Still no Session Drummer.
 
After reading the various posts on this, I'm no longer looking for answers, just lodging a complaint as an unhappy longtime user. I didn't pay for an upgrade so I could spend the next several weeks trying to help you find the bugs in your installer. I have never seriously considered moving to another DAW until this fiasco.
 

Do you have UAC turned on in Control Panel? 

I just spent a good bit of time today on the phone with this problem.  No solution yet. 
 
I tried re-installing the X2 version of SD3, no go.  Did a full re-install of X3, no difference.  Did the ctrl-shift/double click/ok bit, no difference.  Did advanced install of just SD3 from the X3 install, no difference. 
 
I too have also lost SD3 in X2.
 
It exists as it should in the correct folder, containing the dll file.  It is properly referenced in the plug in paths.  It worked before in X2, then disappeared from X2 and never showed up in X3 after the X3 install.
 
It's starting to look to me like all signs are pointing to a conflict with the X3 install, not a conflict with my registries or path assignments.
 
 I'm at a bit of an end for creative approaches to this.  Anyone have any ideas?
 
-Thanks.
 
 
 
#####EDIT DEC 5, 2013#####
 
I realized that Session Drummer 3 was coming up listed in my plugin manager as Session Drummer (no identifier for which version)!  I saw it and Session Drummer 2, but no Session Drummer 3.  Well, I got curious, opened Session Drummmer and found out it's really Session Drummer 3 (face to hand - d'oh!).  I don't know if this threw anyone else off, but hopefully that helps.

Looks like I'm a member of this exclusive club too. I've been using AD and Battery, so I haven't used SD3 x64 in a while. Ran into the exact same situation as the OP. Dragged SD3 in and received a message that it wasn't installed correctly. Reset and rescanned and it completely disappeared from plugin manager. Downloaded X3 again and did a custom install with SD3 only. No go. Tried same custom install with X2. Still nothing. Definitely one of the stranger things I've seen in a while.
 
The only possible weirdness I noticed in the registry was that there are only five keys under:
 
HKEY_CURRENT_USER\Software\Cakewalk Music Software\SONAR Producer\Cakewalk VST X64\Inventory\c:/program files/cakewalk/vstplugins/Session Drummer 3/SessionDrummer x64.dll
 
isBad=0
isVst=0
isVst3=0
modStats has all zeros
touch=1
 
Most of the other synths have a lot more keys, so I'm not sure if that has anything to do with it. I probably wouldn't have even noticed this problem for a while if I didn't want to check out those Quick Kits that Dan made. ;)