I've encountered a bug after I upgraded MusicLab's RealLPC and RealStrat to 4.0.0.7239: when I try to insert the instruments directly from the plugin menu, I can no longer call up the synth's properties window. However, if I insert it from a template I created a while back (to automatically add on IK Multimedia Amplitube), the window comes up. (All other instruments still respond normally)
 
I have Cakewalk SONAR X3 (x3e build 2246) running under Windows 7 (which I hope to upgrade to 10 soon)

I think there is an option on the  synth's properties window that lets bypass (you not see) the properties window every time you open a synth. this might have become ticked by accident or possibly the upgrade set it off somehow.
go to the synth rack and look for Synth options / properties. open the properties options and un tick it.

No no, I'm certain that option is ticked; I've checked it time and time again when trying this very thing—I even have it ask me every time. In fact, I can't even open it when I right-click on the synth and click Synth Properties…
 
I've also found that, even when Enable MIDI Output is ticked, that option won't stay ticked when I right-click.
 
You know, I'm only posting here because I've already contacted MusicLab about this, but they say they can't reproduce the issue. I still wonder which program is to blame, but I'd like SOME answers.

New discovery: when I load the template and right-click on the Amplitube FX on the track OR when I bring up the Browser and click on the Plugins tab and then the Instruments button, Cakewalk then throws up a pop-up window claiming that it can't find the RealStrat CLSID, prompting me to choose one from a list.

When I encountered this problem, I knew it might have had something to do with the fact that I was foolishly keeping open a project with the RealGuitar products while trying to simultaneously update those same products. Anyway, I started thinking the registry might have something to do with it. So I started poking around, and lo and behold, in the HKEY_CURRENT_USER\Software\Cakewalk Music Software\SONAR Studio\Cakewalk VST\Inventory folder, the clsidPlug and clsidProps entries for each product had somehow been erased! Fortunately, this had only happened for the first entry; there seemed to be a duplicate in each one with the correct values. Once I copied each entry, I discovered I can now view them properly again!

Thread can now be closed and locked, but keep this up for those who have had similar trials!