FAQ.md

@@ -49,7 +49,7 @@
 * **gdxxrw failed**
     * The tool, that converts your excel sheet into GAMS data failed. That is usually caused by mistakes in the backbone command line (Did you spell the pathes right? Did you use the right amount of quotation marks?). Gdxxrw can also fail, if you have double entries in your excel sheet (e.g. twice the unit "lignite powerplant 1" in the unit sheet).
 * **symbol not in gdx**
-    * A set or parameter is not included in the input data. Click on the error message to find out, which parameter causes the problem. Check your input data, whether the set/parameter is a sheet in the excel file and has a row in the index-sheet of the excel file.
+    * A set or parameter is not included in the input data. Click on the error message to find out, which parameter causes the problem. Check your input data, whether the set/parameter is a sheet in the excel file and has a row in the index-sheet of the excel file. This error can also occur, if your input data was prepared for another backbone version than the one you have downloaded. Ask your supervisor if in doubt.
 # Pypsa-eur
 * **When using pypsa-eur, I get the error "symbolic privilege not held".**
     * You must run the shell you are using as administrator.