Sonar X2 opens but when I open a project of mine it gives me a BEX 64 event/sonarpdr.exe crash.  I looked it up and it said it was a buffer issue in the system.  I have been running Sonar perfectly for years and this just started today.  Just curious how I fix this issue.  Thanks

32 or 64 bit ?
install any soft synths recently ?
anything new installed recently ?
or possibly used a plug in you haven't used in a long time ?

I am on 64 bit. I went through my projects tonight and only one will not open (thankfully).  I am using sonars plugins with Superior Drummer, Omnisphere and Massive.  I have recently installed Kontakt 5 within the last month but everything has worked up until today.  I went back to open that project and as soon as it loads it freezes then gives me that message.  That BEX 64 event crash seems like it happens to other executable files from what I have found.  It also happened on another search in Sonar X1 and it ended up being a bad .dll file.  That doesn't make since since I can open up all of my other projects using the same .dll.  Hmmmm

Try opening the errant project in safe mode (hold Shift whilst opening), disable all plugins and see if it opens properly.
 
If it does then you know it's a plug that's causing the problem so you can start eliminating them one by one by doing the safe mode thing repeatedly until you find the one causing problems.
 
If it doesn't then it's likely your project is corrupt and you might be faced with rebuilding it.