Indicates the API was wholly misused (see err for more). Cases where these can be returned are documented, but generally indicates some precondition of a function was violated.

Due to a high feerate, we were unable to complete the request. For example, this may be returned if the feerate implies we cannot open a channel at the requested value, but opening a larget channel would succeed.

An attempt to call add_update_monitor returned Err ( ie you did this!), causing the attempted action to fail.

a malformed Route was provided ( e.g. overfloed value, node id mismatch, overly-loope route, too-many-hops, etc).