For a few maps in a few surveys I have been using the -survey option to constrain map statistics to match the underlying survey (page 34-35 of Therion Book).

I think some recent version of Therion has broken this.

The start of my map definition…

  map MiddleEarthElev290Map \

  -title "Middle Earth and<br>Lower Greenlink Caves<br>Elevation looking 290 deg" \

  -projection [elevation 290 deg] \

  -survey MiddleEarth # survey option forces map statistics to match the survey

The error reported…

via Mapiah…

C:\Program Files\Therion\therion.exe: error -- Press ENTER to exit!./GreenlinkArea/./middleearthcave/INDEXMiddleEarthElev290.th [579] -- invalid survey reference – MiddleEarth

via XTherion

C:\Program Files\Therion\therion.exe: error -- ./GreenlinkArea/./middleearthcave/INDEXMiddleEarthElev290.th [579] -- invalid survey reference -- MiddleEarth

writing xtherion file ... done

I am using… therion 6.3.4+d9c313ac (2026-03-29)

  - using Proj 9.8.0, compiled against 9.8.0

Anyone else noticed this?

Thanks

Bruce