[Therion] data nosurvey

Hi all I have 2 stations connected by sight only so I tried data nosurvey from to 2.1 2.9 full file attached, which works with the 2 lines above commented out, but with them in I get the error therion: error -- unsurveyed shot between unfixed stations -- StalPotInlet.th [95] Which is true, they are not fixed any help connecting these 2 stations with a centreline, to show line of sight would be useful thanks Andrew