In script, Point to Raster generates Error 999999 : Failed to build pyramid

I have a script that for various reasons is converting point data into polygons by going through raster format first. However, the script is failing with the message:

Traceback (most recent call last):
File "<string>", line 580, in execute
File "c:\program files (x86)\arcgis\desktop10.1\arcpy\arcpy\conversion.py", line 2393, in PointToRaster
raise e
ExecuteError: ERROR 999999: Error executing function.
Failed to build pyramid
Failed to execute (PointToRaster).

The code looks like this:

arcpy.AddMessage("\nCreating raster.")
arcpy.MakeFeatureLayer_management(tmp_point, "points")
arcpy.PointToRaster_conversion("points", "ID_FIELD", tmp_grid, "MOST_FREQUENT", cellsize=Resolution)
arcpy.AddMessage(" - Finished creating raster.")
arcpy.Delete_management("points")

Not sure what is causing the issue, if it is related to the script or if this should be in the Imagery and Rasters section.

Thanks!