# Asterisk 20.21.0 app\_queue deadlock with shared\_lastcall enabled

**URL:** https://forums.vitalpbx.org/t/asterisk-20-21-0-app-queue-deadlock-with-shared-lastcall-enabled/6472
**Category:** Reporting an Issue
**Created:** [October 10, 2026, 8:58pm UTC](https://forums.vitalpbx.org/t/asterisk-20-21-0-app-queue-deadlock-with-shared-lastcall-enabled/6472 "2026-10-10T20:58:19Z")
**Posts on this page:** 1
**Showing post:** 2

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### Author: ![miguel](https://forums.vitalpbx.org/user_avatar/forums.vitalpbx.org/miguel/32/415_2.png) [@miguel](https://forums.vitalpbx.org/u/miguel)
#### Post date: [October 15, 2026, 11:49pm UTC](https://forums.vitalpbx.org/t/asterisk-20-21-0-app-queue-deadlock-with-shared-lastcall-enabled/6472/2 "2026-10-15T23:49:59Z")

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This is addressed in the latest vitalpbx update.

> [@VitalPBX 4.5.4 R2 Released: Smarter Realtime AI Agents](https://forums.vitalpbx.org/t/vitalpbx-4-5-4-r2-released-smarter-realtime-ai-agents/6474):
>
> We are excited to announce the immediate availability of VitalPBX 4.5.4 Release 2! This release delivers major reliability and intelligence upgrades across the entire platform. Highlights include an upgraded Asterisk v20.21.0 R2 engine fixing a critical queue deadlock issue, native Caller ID pass-through and audio flow control for Realtime AI Voice Agents, refined hot desking caller ID handling, and more. shield Critical Engine Upgrade: Asterisk v20.21.0 R2 (app\_queue Deadlock Fix) For call…

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