better error reporting

when there is an error with an alignment, the software doesn't tell you where that error actually. You just get the red "i" next to the alignment, saying 2road/feature self interesects" or "cannot merge with finished surface"

This is very frustrating having to go through the whole alignment looking for a miniscule error, which is usually caused by software limitation (sometimes a channel is a bit wobbly, and could got a little backwards)