iPhoto not launching after upgrading to OS X 10.10, Yosemite
I found a proper solution to this problem:

I had used the Migration Assistant to migrate my old Mac System (10.8 or so) to a newly bought Mac Mini with 10.10 (Yosemite). After a few day I found out that iPhoto wasn’t starting — with the described symptoms.

Fortunately I still have the old system running, so I could compare them and copying the old NyxAudioAnalysis directory did the job. 

Everything could be fine here, but I wondered why when reparing my access rights the disk utility kept telling me there was a problem with the directory. It said it was a directory, but was expected to be a symbolic link:

Abweichende Zugriffsrechte für „Library/Frameworks/NyxAudioAnalysis.framework“, Soll-Wert: lrwxr-xr-x , Ist-Wert: drwxr-xr-x .


(German version here, sorry.)

Since I have another box running under Yosemite I could compare the systems and I found out that Apple had moved the location of the NyxAudioAnalysis framework at some time. In 10.10 (Yosemite) it is located in /System/Library/PrivateFrameworks, whereas in older systems it was in /Library/Frameworks. To ensure compatibility, Apple inserted a symlink at the old location: NyxAudioAnalysis.framework → /System/Library/PrivateFrameworks/NyxAudioAnalysis.framework. The migration assistant seems to have messed that up somehow. 

So to fix it you can use Terminal.app: 

cd /Library/Frameworks
sudo mv NyxAudioAnalysis.framework NyxAudioAnalysis.framework.copy
sudo ln -s /System/Library/PrivateFrameworks/NyxAudioAnalysis.framework NyxAudioAnalysis.framework


which does the job.

Conclusion: Copying the directory from some source is working, but it may not last. The potential problem with it is that if Apple should update their library some time you won’t get the changes. This could cause some problems with iPhoto (or other programs) any time in the future. Therefore I suggest to insert the original symbolic link.