Unilateral close because of HTLC in remote commitment

[Bitcoin]

Unilateral close because of HTLC in remote commitment

I run lnd on my node and sometimes see messages like this:

[INF] CNCT: ChannelArbitrator(CHANPOINT): immediately failing htlc=HTLCID from remote commitment

The corresponding close transaction sent out by my node does not contain any HTLC output. I'd like to understand more about this situation, and what I can do to avoid this.

• How does the HTLC end up in my peer's commit transaction?


• Why does my node know about it, but doesn't have the HTLC in the local commitment transaction?


• Why isn't it necessary to recover the HTLC funds as part of the close transaction?


• What went wrong, i.e. how can I help avoid this kind of channel closes?

This is the corresponding code in lnd: https://github.com/lightningnetwork/lnd/blob/cd8a87c0daf569404f6bcf8e839524f0e639d881/contractcourt/channel_arbitrator.go#L1806

Related to Under what conditions would lightning channels be force closed automatically?

Source: Unilateral close because of HTLC in remote commitment