There does seem to be a conflict of some kind with AmpliTube 3. One day I couldn't open a project I was working on that had AmpliTube, it would keep crashing. It had opened successfully several times before, but after it didn't open once, it wouldn't open again. 

I grabbed the latest AmpliTube update. In Sonar, I use a 64-bit system so I made sure it "saw" the 64-bit version and not the 32-bit one. I then opened the project in safe mode, inserted AmpliTube, recalled the presets I'd used originally, and "saved as" the project. 

I'm not sure which one of these changes was the fix, but I haven't had any problems since.

Thanks for the corroboration.  I'd like to get another person that has issues with Amplitube products (or doesn't have a problem with it) and I'll go to tech support about it, or maybe I'll just do it this week.

I did the same and the project worked fine, but the past two days I did the same for a diff project and I could not open in... 3 crashes on opening.  Opened it in safe mode... took out one Amplitube 3 track.  Resaved.  The next day, still 3 crashes on opening, but I did get an error message about "no output assigned to Solo Track,"  but it shows output to the master track on opening and plays fine.  Almost like the loading of the VST output has a program conflict.  Haven't noticed any other issues on these two recent projects.

I'm running a template with hmm lets see, 3 doubletracked guitars, 1 solo guitar in mono and a bass, that's 8 instances of Amplitube3, never had any crashes caused by amplitube as far as I know.

I only get crashes when loading or deleting random vsts, as soon as they are loaded and going it's pretty stable.

I only have the 64 bit version installed though, I'm runnning 100% 64 bit so there may be something with mixed 32/64 bit that causes it?

When IK changed to the Authorizer, load time for my IK plugins became several seconds.  If you think that Rapture must load in, "miliseconds," it seems that Amplitube could load in 10?

All my seperate versions of Amplitube are so old, and I doubt I will upgrade them..   Actually, for us guys who got LE through a package givaway, than upgraded it, and bought some sort of metal version, and got another version through a different purchase..  IK has really managed to make our payware copies useless with their Free IK Amplitube 3 version...  It doesn't everything my former payware does..  whatever modules are missing, or you want, you can pick up for pennies in their custom shop...

Meanwhile..  I've bought several IK products, and now they are sitting around collecting, "real, or virtual." dust...

Now add their incesantly annoying social media campiagns, and the fact that I have all but disliked them on facebook..  and the criticms can just keep coming...

Edit = let me just sum up..  because I don't want to get into any argument here.  "i used to like em on Facebook.  I no longer do.