HTC halts U11 Android 9.0 Pie update rollout following reports of bricked phones
Specifically, after updating to Android 9.0 Pie, HTC U11 users couldn't get past the PIN code or pattern to unlock their phone. Although HTC pulled the update soon afterward, many U11 users have had their devices soft-bricked. In a thread on HTC's official forum spotted by XDA Developers, the company promised to send its engineers to repair these units at designated locations.
According to HTC, the free service is only offered to those U11 users who can't get past the PIN code or pattern to unlock their phones. Another interesting recommendation made by HTC is that U11 owners who already updated to Android 9.0 Pie and don't receive any errors after they insert their PIN code, should not install the WeChat app for the moment.
For the time being, HTC hasn't yet offered any ETA on the re-release of the update, so your guess is as good as ours. If you own the HTC U11, we'd recommend waiting a few more days after the Android 9.0 Pie rollout is resumed.