[bug]: Unable to make payments due to "insufficient balance" despite adequate liquidity

[Liongrass]

Background

I now ran into a "FAILURE_REASON_INSUFFICIENT_BALANCE" error twice when making a payment with lncli. I checked that I had more than enough local balance, and that the channel was active. Both times a restart fixed the error.

Your environment

• lnd 0.19.1-beta commit=v0.19.1-beta
• linux 6.8.0-60-generic
• bitcoind 250100
• occurs both with and without litd

Steps to reproduce

I do not know how to reproduce this error.

Expected behaviour

I expect the payment to at least be attempted, as the first hop has enough liquidity.

Actual behaviour

I cannot make payments out through the channel in question.
I have enough liquidity in the channel and the channel is active.
I can make payments through that channel in the other direction and I can route payments in both directions.
There are no pending HTLCs in that channel either.

Log snippets when using a fee limit of 0 ( as it's a direct peer):

2025-07-02 10:29:18.453 [DBG] RPCS: [/routerrpc.Router/SendPaymentV2] requested
2025-07-02 10:29:18.478 [DBG] CRTR: Payment efde39b4feff96c7d21b65a2c9e327f9c59be04e46fa8fb22b888bac8b1b4b75: status=Initiated, active_shards=0, rem_value=1000000 mSAT, fee_limit=0 mSAT
2025-07-02 10:29:18.478 [DBG] CRTR: PaymentSession(efde39b4feff96c7d21b65a2c9e327f9c59be04e46fa8fb22b888bac8b1b4b75): pathfinding for amt=1000000 mSAT
2025-07-02 10:29:18.479 [WRN] CRTR: ShortChannelID=816213:2287:2: link not found: channel link not found
2025-07-02 10:29:18.479 [DBG] CRTR: Pathfinding absolute attempt cost: 101 sats
2025-07-02 10:29:18.482 [DBG] CRTR: Pathfinding perf metrics: nodes=2, edges=82, time=3.809694ms
2025-07-02 10:29:18.482 [DBG] CRTR: PaymentSession(efde39b4feff96c7d21b65a2c9e327f9c59be04e46fa8fb22b888bac8b1b4b75): not splitting because minimum shard amount 10000000 mSAT has been reached
2025-07-02 10:29:18.482 [WRN] CRTR: Failed to find route for payment efde39b4feff96c7d21b65a2c9e327f9c59be04e46fa8fb22b888bac8b1b4b75: unable to find a path to destination
2025-07-02 10:29:18.482 [WRN] CRTR: Marking payment efde39b4feff96c7d21b65a2c9e327f9c59be04e46fa8fb22b888bac8b1b4b75 permanently failed with no route: no_route
2025-07-02 10:29:18.496 [ERR] CRTR: No route found for payment efde39b4feff96c7d21b65a2c9e327f9c59be04e46fa8fb22b888bac8b1b4b75
2025-07-02 10:29:18.497 [DBG] CRTR: Payment efde39b4feff96c7d21b65a2c9e327f9c59be04e46fa8fb22b888bac8b1b4b75: status=Failed, active_shards=0, rem_value=1000000 mSAT, fee_limit=0 mSAT

When forcing the channel with --outgoing_chan_id:

2025-07-02 10:30:36.661 [DBG] RPCS: [/routerrpc.Router/SendPaymentV2] requested
2025-07-02 10:30:36.686 [DBG] CRTR: Payment 83de503403f3d0930459276357777bc30e4e804d4035a99379eba6200f383fba: status=Initiated, active_shards=0, rem_value=1000000 mSAT, fee_limit=1000000 mSAT
2025-07-02 10:30:36.686 [DBG] CRTR: PaymentSession(83de503403f3d0930459276357777bc30e4e804d4035a99379eba6200f383fba): pathfinding for amt=1000000 mSAT
2025-07-02 10:30:36.686 [WRN] CRTR: Not enough outbound balance to send htlc of amount: 1000000 mSAT, only have local balance: 0 mSAT
2025-07-02 10:30:36.686 [DBG] CRTR: Pathfinding perf metrics: nodes=0, edges=0, time=41.571µs
2025-07-02 10:30:36.686 [DBG] CRTR: PaymentSession(83de503403f3d0930459276357777bc30e4e804d4035a99379eba6200f383fba): not splitting because local balance is insufficient
2025-07-02 10:30:36.686 [WRN] CRTR: Failed to find route for payment 83de503403f3d0930459276357777bc30e4e804d4035a99379eba6200f383fba: insufficient local balance
2025-07-02 10:30:36.686 [WRN] CRTR: Marking payment 83de503403f3d0930459276357777bc30e4e804d4035a99379eba6200f383fba permanently failed with no route: insufficient_balance
2025-07-02 10:30:36.699 [ERR] CRTR: No route found for payment 83de503403f3d0930459276357777bc30e4e804d4035a99379eba6200f383fba
2025-07-02 10:30:36.699 [DBG] CRTR: Payment 83de503403f3d0930459276357777bc30e4e804d4035a99379eba6200f383fba: status=Failed, active_shards=0, rem_value=1000000 mSAT, fee_limit=1000000 mSAT
2025-07-02 10:30:36.699 [WRN] CHDB: Payment(83de503403f3d0930459276357777bc30e4e804d4035a99379eba6200f383fba): cannot register HTLC attempt: payment has already failed, current status: Failed
2025-07-02 10:30:36.700 [ERR] CRTR: Payment 83de503403f3d0930459276357777bc30e4e804d4035a99379eba6200f383fba failed: insufficient_balance

Full logs and go profile:

2025-07-02_goprofile.txt

2025-07-02_lnd.log

[yyforyongyu]

Think outgoing_chan_id is deprecated tho. This is a normal channel right? Not alias channel?

[Liongrass]

Yes this is a normal, public channel. I also checked lncli listchannels and lncli getchaninfo but everything seemed normal.