No it's not a limit issue, something is generating an invalid waypoint id.
Sandbot is one of many things that I work on (
http://www.teamsandpit.com/#sandpit,
http://www.teamsandpit.com/#zcmp,
http://www.teamsandpit.com/#basis,
http://www.teamsandpit.com/#gssmt as well as other private/unannounced stuff) so things like this take time.