[bug]: unable to close channel: rpc error: code = Unknown desc = link failed to shutdown

[Silarous]

Background

I am attempting to close my last channel on this node and when I enter "lncli closechannel" or "lncli closeallchannels" it produces the error

"unable to close channel: rpc error: code = Unknown desc = link failed to shutdown"

I've closed all my other channels on this node without issue. This is the last one. The channel is listed as active in both RTL and when I run "lncli listchannels". This channel is over 3 years old.

Your environment

• LND 0.16.1-beta commit=v0.16.1-beta
• Debian 5.10.162-1 (2023-01-21) x86_64 GNU/Linux
• Bitcoin Core RPC client version v24.0.0

Steps to reproduce

lncli closechannel
lncli closeallchannels

Expected behaviour

Close the channel

Actual behaviour

Produces the error "unable to close channel: rpc error: code = Unknown desc = link failed to shutdown"

[Roasbeef]

You may need to force close the channel, what do you see in the logs when you try to do a co-op close?

[Silarous]

This is what is listed in the lnd.log during attempted channel close

2023-08-22 09:50:52.487 [INF] PEER: Peer(): Local close channel request delivered to peer
2023-08-22 09:50:52.493 [INF] PEER: Peer(): Delivery addr for channel close: bc1*************************************
2023-08-22 09:50:52.493 [ERR] PEER: Peer(): failed link shutdown: link failed to shutdown
2023-08-22 09:50:52.493 [ERR] RPCS: [closechannel] unable to close ChannelPoint(************:0): link failed to shutdown
2023-08-22 09:50:52.493 [ERR] RPCS: [/lnrpc.Lightning/CloseChannel]: link failed to shutdown

[Crypt-iQ]

you have outstanding updates on your commitment tx, dupe of #6039