I am utilizing Sonar X2 Producer, with Windows 10.  I have 5 bundle files that suddenly will not open out of 100's of files.  I have opened these files many times.  I have gone back to restore points in hopes of identifying the issue, with no luck.
Any suggestions?

Have you tried opening them is safe mode? Hold down the shift key while opening the file. This allowed me to save a corrupted project a couple of weeks ago. Often it seems like an errant plugin can be the culprit. It was in my case.
 
Good luck!

Thanks.  That at least brought the file up and played great.  Saved it as a new bundle, opened it again, which I was happy it opened, but absolutely no sound, midi or audio.  At least the file will open, that's a lot further along then I was.  thank you

Oh Oh, the dreaded BUN rears it's ugly head... 
Always save your work in a few formats. BUN files have gone bad in the past and there seems no real solution. I've never used them myself but over time there seems to be some one with your issue form time to time. Yet it's rare to see someone complain about CWP or MID files. 
The best practice is to always save all your work as a CWP and a MID file as well. Only takes a second and takes up very little storage if in the same folder.