To validate Xcode: "in sealed resource is missing or invalid"

I get the same error, too. I have replaced the black DVTIbeamCursor.tiff cursor with a white one (because I use a dark colour scheme and apparently Apple doesn't believe that I should use anything other than an eye-straining bright scheme). I wonder if that could have caused it? I used to save the original cursor but after quite a few versions of successfully changing this everytime I install a new Xcode, I decided there was no need to bother.

No, that's definitely not it. Gatekeeper is set up to allow apps from "Apple" in addition to the App Store and identified developers.

Yeah, I suppose that's true. I've always gotten my Xcode directly from Apple, so I'm 99% sure mine is all good, but I was still worried about others who were tricked into getting the counterfeit one. Now that others have pointed out that the App Store is still secure and tightly controlled and that all the malware could do was look at the sandbox and phish for information, I feel a lot less worried about the integrity of the whole system.

I too got the same error at the first time. I think its because of Gatekeeper settings. When I changed my Gatekeeper setting to 'Anywhere' , I am getting this result for "spctl" --- "spctl"

/Applications/Xcode.app: accepted

override=security disabled

Not sure, whether its OK or not ?

The fact that you had to disable Gatekeeper in order for it to be nice indicates that it doesn't like the copy of Xcode.

I'm starting to think that the directions about spctl verification were inaccurate.

Edit: Apparently spctl performs some kind of caching that causes it to fail even though the app itself is good, if it recently failed. Running spctl on my 7.0 (7A220) Mac App Store copy now succeeds.

I just learned this—apparently the counterfeit Xcode issue was mostly confined to China. Check out this FAQ page from the Chinese version of the website:

http://www.apple.com/cn/xcodeghost/