I'm trying to join a shp and a CSV, by joinbyattibutes, by the Column "KOMNAVN" in QGIS 2.18.
However, I get this log message error and I can't figure out what I'm doing wrong.
Search for the tool
Convert Geometry Type and convert your layer to the type that should be.
I faced this problem, it was a problem of a strange geometry type that was not supported.