Logic Pro X will not open projects post 10.2 update

Well, I very much appreciate your input so far! It's been helpful.

So, I'm about to step out to go to work (on New Year's, whoo) but I'll look into the plists when I can. Do you know how to fix a problem like this? The plist is just preferences, isn't it? Or am I thinking of another P labeled file? Well, I'll look into it when I can. Hopefully the people you mentioned might see this thread.

I also updated all of my Arturia software so we'll see if that changes anything.

Okay, so I followed the log back to where it says the problem files are at and here is what I've found.

I've included some screen shots to show what I'm looking at.

The first shows the components that are causing the problems as shown in the log. The second shot shows the contents of the plist of the first plugin in the log results, the ARP 2600 V2. I got to this screen by right clicking the component and clicking, Show Package Contents. Notice how the components mentioned in the log are the same components that have different logos in the window. I wonder if that's due to the "corruption"?

Now, I'm looking at the log and the plist itself and I'm finding the parts that the log is referring to. But now that I've found this stuff, what do I do with it? I couldn't imagine that any of the values have changed by my doing so any idea on where to go from here?

I believe I have resolved the issue!

I sent a support ticket to Native Instruments, and they returned with something unrelated to the Arturia messages in the validation log. Apparently, here's what they have on their website regarding the matter.

"Products with a hardware dependency, such as MASCHINE, KOMPLETE KONTROL, TRAKTOR, GUITAR RIG, and Controller Editor will not launch when the AVID CoreAudioManager / Drivers are installed under 10.10 Yosemite. In stand-alone mode the application will freeze after launching, in plug-in mode the plug-in validation of the host program will fail, which might crash or freeze the host program or make the plug-in unavailable within the host program.

Native Instruments and Avid are working together to resolve this compatibility issue."

All I had to do was copy the Avid CoreAudio plugin to the desktop and delete it from its original location. As of now, everything is up and running again! I'm hoping that update they mentioned will come out soon to fix this problem.

Thanks for all the help though! You've been very helpful!