I am trying to open and edit a station map, and I have been able to before in the past.

However I get the error:
6092:error: unexpected input: #

I can still edit other maps no troubles it's only this one.
try it in both the beta and the stable.

also consider posting the map file here so we can inspect it for errors that wouldn't prevent its loading but might prevent editing.
I found the problem, but thank.