I've never heard of "ONCoreFoundation7.dll". But Apple products use a file called CoreFoundation.dll. So I'd start by reinstalling any Apple software you may have on the computer, including, but not limited to iTunes and Quicktime.
just try updating iTunes.
On my system this error is specific for the OnOne photo suite and appeared after installing PhotoshopCC on a system with Photoshop CS6 already installed. Just reinstalling the OnOne product got rid of the error. Presumably the OnCoreFoundation.dll adds something to the registry relating to the Creative Cloud product. At least that's what worked for me.
This error is related to ONOne Software's 'Perfect Effects 4' program. It has nothing to do with Apple.
When trying to open Photoshop (I have CS5), an error message pops up to tell you that the oncorefoundation7.dll is missing. The file is located in c:\program files\on one software\perfect effects folder and it needs to be copied and pasted in the c:\program files\adobe\adobe photoshop cs5(64bit) folder.
Ok, that fixes the error. Then another error pops up to tell you that the ondocument7.dll is missing. Once again, copy and paste it from and to the previously specified source/target folders.
Ok, that fixes the error. Then another error pops up to tell you that the onproxysupport7.dll is missing. Once again copy and paste it from and to the previously specified source/target folders...and voila! No more errors opening Photoshop.
Isn't it fun? The program developers should be doing this, not users. Luckily, I can usually find a solution to such problems with relative ease.
Generally, all of these steps would be taken care of when installing Prefect Effects. Did you already have it installed (for previous versions of Photoshop) when installing Photoshop CS5? If so, then it is likely a reinstall of Perfect Effects is required when installing new versions of Photoshop.
Many thanks to all on here, as I have just fixed my problems with Elements 9, which started after I tried to update it, not after adding Perfect Effects ;-)