System applications can't connect to the internet, others can

I recently installed OS X 10.10.3 beta (14D87p) and I found that all system applications (App Store, Safari, iCloud, Mail, ...) can't connect to the internet while others (e.g. Google Chrome) can. This happens after a couple of minutes from startup (before this, all apps work perfectly). I would attach the Console output but I can't find error messages that point to the problem, apart some connection timeout errors or

11/03/15 18:32:56,157 AppleIDAuthAgent[830]: AppleIdAuth URL Error: Error Domain=AOSErrorDomain Code=1000 "The operation couldn’t be completed. (AOSErrorDomain error 1000.)"

11/03/15 18:32:18,000 kernel[0]: Sandbox: appleeventsd(25) deny file-read-metadata /Library

11/03/15 18:32:18,000 kernel[0]: Sandbox: appleeventsd(25) deny mach-lookup com.apple.ocspd