Hi @Hiro -
A KeyError usually happens when there is a Value in the land use/land cover (LULC) raster that is not also in the biophysical table. So if you have an LULC Value of 255, make sure that it has a row in the biophysical table.
There is also an issue in the models where they sometimes don’t handle NoData values properly. If your LULC raster has a NoData value of 255, you can work around this problem by adding a row for lucode 255 to the biophysical table, and assign any value to usle_c and usle_p (a value of 0 is fine.) This will not affect the results, but will allow the model to continue.
~ Stacie