Error codes can be encountered when sending a payment or interacting with the Lightning Network via an implementation.
ErrNoPathFound is returned when a path to the target destination does not exist in the graph.
ErrNoRouteFound is returned when the router is unable to find a valid route to the target destination after fees and time-lock limitations are factored in.
ErrInsufficientCapacity is returned when a path if found, yet the capacity of one of the channels in the path is insufficient to carry the payment. ErrMaxHopsExceeded is returned when a candidate path is found, but the length of that path exceeds HopLimit. ErrMaxHopsExceeded ErrTargetNotInNetwork is returned when the target of a path-finding or payment attempt isn't known to be within the current version of the channel graph. ErrTargetNotInNetwork ErrOutdated is returned when the routing update already have been applied, or a newer update is already known. ErrOutdated ErrIgnored is returned when the update have been ignored because this update can't bring us something new, or because a node announcement was given for node not found in any channel. ErrIgnored ErrRejected is returned if the update is for a channel ID that was previously added to the reject cache because of an invalid update was attempted to be processed. ErrRejected ErrPaymentAttemptTimeout is an error that indicates that a payment attempt timed out before we were able to successfully route an HTLC. ErrPaymentAttemptTimeout ErrFeeLimitExceeded is returned when the total fees of a route exceed the user-specified fee limit. ErrFeeLimitExceeded
ErrMaxPendingChannels is returned by remote peer when the number of active pending channels exceeds their maximum policy limit.
ErrSynchronizingChain is returned by a remote peer that receives a channel update or a funding request while their still syncing to the latest state of the blockchain.
ErrChanTooLarge is returned by a remote peer that receives a FundingOpen request for a channel that is above their current soft-limit.