Google has temporarily deactivated a security feature designed to make it harder to make illicit copies of apps for the latest version of its Android mobile OS, owing to a bug that rendered the secured versions of some apps inoperable.

The feature, which was introduced with Android 4.1 "Jelly Bean," encrypts all paid apps downloaded from the Google Play store with a device-specific key. Apps so encoded will only run on the device that originally downloaded them, even if the user manually copies them to another device using backup software.

Shortly after the new feature debuted in July, however, reports started trickling in to Google's Android bug database that some users were having a hard time launching apps on their Jelly Bean devices, even though theirs were legitimate copies.

The root of the problem appears to be a defect in Android 4.1's system startup code, which corrupts affected apps whenever the user powers on or reboots the device.

According to the latest reports, however, users who have deleted the affected apps and then downloaded them again using the latest version of the Google Play Store have seen the problems disappear.

The re-downloaded apps are now installed in the unencrypted portion of the Android device's memory, where they are stored on earlier versions of Android, which indicates that Google has deactivated App Encryption for Jelly Bean devices until it can produce a fix.

Google did not respond to The Reg's request for comment on the problem. As of last Wednesday, however, the bug's status has been marked "FutureRelease" in the online ad-slinger's database. That means it has been recognized as a legitimate Android bug and will be fixed in a future OS update, although no time frame has been given.

The delay is bound to disappoint developers who have been hoping that App Encryption would cut down on illegal app copying among Android users. In July, software developer Matt Gemmell wrote a lengthy diatribe against Google's mobile OS, saying that compared to Apple's locked-down iOS ecosystem, the Android platform is "designed for piracy."

In truth, however, most developers will be little affected by the sudden – and presumably temporary – loss of App Encryption, because not many of their customers' devices support it in the first place. So far, Jelly Bean is only available for a limited set of kit, including Google's Nexus devices and the Motorola Xoom, with the majority of Android devices are still running version 2.3 of the OS. ®