I recently released an OS X app for the Mac AppStore (after successfully browsing Apple apps). If I try to install this application through the AppStore, I get this error, shown immediately after clicking the install button (even before the actual download):
"App Store Error: Failed to verify the preflight file. It is not signed by Apple."
I found a general hint / some potential problems associated with this Keychain settings error message: http://manytricks.com/blog/?p=3339
Changing these settings (even deactivated for OCSP and CRL) did not solve my problem. I also reproduced this problem on an empty system, without which this application was never installed. I could run the application from the downloaded xcarchive package without any problems, and the process of checking for Xcode / iTunesConnect did not reveal any problems.
This is the appropriate system console log:
16.02.16 18:07:39,597 storedownloadd[458]: *** Assertion failure in -[CheckPreflightOperation verifyDistributionAtURL:allowsDevSign:allowsUnsigned:osVersionToBeInstalled:error:distributionController:], /SourceCache/Commerce/Commerce-376.29/CommerceKit/CheckPreflightOperation.m:307
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