QGIS cannot use esri'sEsri's geometry format so the error you are seeing ifis caused by something else.
When you create a feature class in arcgisArcGIS and specify that you want to use the PG_GEOMETRY option, arcgisArcGIS registers the table as having a generic geometry type column. You can see this in the public.geometry_columns table postgisPostGIS uses as a central registry of spatial tables.
You should change this to a specific geometry type, like POINT, LINESTRING, POLYGON, MULTILINESTRING or MULTIPOLYGON.
The naming of spatial types and functions are many times equal between postgisPostGIS and esriEsri. The big difference is that esriEsri stuff in stored in the sde schema. PostgisPostGIS keeps these things in the public schema.