Matthew wrote: Perhaps if you to the Lightworks settings in the material settings dialog and click on "match with internal engine", that might clear it up.
hmm. I had 'disable unrelated controls' on so I didn't see that.
Nevertheless, it made it worse.
It was something with the scale indeed.
Solution was to make a new texture, and than the origin was directly on the right place (because the wall was there before the texture was first placed I guess.) After that scaling was not a trouble.
When this project is finished, I make a list with things that are difficult to learn in ArchiCAD. Surely if your native language is not English and some terms are difficult to understand...