This has been really hard to debug, as I had no idea where to look at first, but I have made an attempt to access the "valueField" property of a layer file. This layer file is of the UNIQUE_VALUES symbology type (although I knew it, also successfully tested with code), and thus must have a **read/write** valueField property associated with it according to the Help (http://resources.arcgis.com/en/help/main/10.2/index.html#//00s30000005s000000). However, as soon as I try to access it like: valField = lyr.symbology.valueField the script stops dead in its track. Not knowing exactly how to access it (there is only a write example in the Help), I also tried: valField = lyr.symbology.valueField() to know avail. I then noticed in PyScripter, after further configuration of Pyscripter to allow auto-completion with arcpy, that there is no valueField property / method shown... See the first screenshot (no, it's not down the scrollable list). The second screenshot shows I have configured PyScripter properly, as you can see the arcpy auto-completion at work. What am I missing? I am able to successfully access other properties like labelClasses. ArcGIS 10.2.0 by the way... ![lyr.symbology.valueField][1] ![lyr.symbology][2] [1]: https://i.sstatic.net/qIzxo.jpg [2]: https://i.sstatic.net/eqdd0.jpg