If you have a large repository containing binary files merges often take longer than a minute. The error "Server Unreachable" is given even though the merge is still occurring behind the scenes.
The server allows the merge up to 5m (configurable) to complete and the UI (not configurable) would have to be willing to wait the same amount of time the server is willing to wait but it is currently hard-coded (1 minute).
It would be good to have a more informative message for these cases, or at least the ability to turn off the error message so that developers don't think that something has gone wrong. A loading bar for these large merges would be ideal.