i was wondering if somebody could please help me with the raster calculator (map algebra). My raster is in the GRID format, source type is continuous and pixel type is floating point (32bit). If i use the raster calculator ("dem" *1000 or "dem >= 2m" (to highlight certain heights) it gives me the following error: ERROR 000539: Error running expression: rcexec() <type 'exceptions.ImportError'>: No module named collections.