What does HRESULT 0x88980408 (UCEERR_CONNECTIONIDLOOKUPFAILED) mean?

UCEERR_CONNECTIONIDLOOKUPFAILED

UCEERR_CONNECTIONIDLOOKUPFAILED is a Windows User Composition Engine (UCE) HRESULT. It indicates that a composition command refers to a channel connection that is no longer valid or was never established.

What to check for UCEERR_CONNECTIONIDLOOKUPFAILED

• Check dispatcher shutdown, application exit, and window-close paths for pending rendering work.
• Do not retain callbacks that submit visual updates after their owning UI context is gone.
• Capture preceding transport or render-thread errors that may have disconnected the channel.

Microsoft guidance for WPF render-thread failures

Diagnostic discriminator: Trace the composition connection identifier used by the failing command and verify that the connection is still registered. The discriminator is a stale or nonexistent channel connection, not a generic render failure.