On Sat, Jan 12, 2019 at 10:51 AM Michael <knollesimage@t-online.de> wrote:

I have now attached a minimal cave sample produced  with 5.4.1. and one produced with 5.4.2. to demonstrate the displacement.

 

Hi,

the problem is that EPSG:31467 projection uses the "potsdam" datum and the PROJ library used by Therion changed the way how to transform potsdam datum to the standard WGS84 datum – it switched from a simple string parameter (towgs84) to using external grid file (see https://proj4.org/resource_files.html#transformation-grids for examples). 

No grid files are currently included in the windows Therion distribution, so the transformation is not correct in 5.4.2. Therion needs to be modified to include and use those files – hopefully soon.

Best regards

Martin