FYI, I've been getting the same error and it's starting to drive me nuts. I know where the BasinHeader table is, it's added to the map, I've opened it to verify that it's real, and I specified the location of it using the Data Management tool in the GeoHMS toolbar. Still get the same error every time, and as a result I need to manually input the geometry information in HEC-HMS. Kinda defeats the purpose of using the toolbar. So any updates from someone with a fix are still welcome. Thanks GH 12/12/2013 Using version 10.1 I had to make sure that the BasinHeader Table was in the correct geodatabase which required moving the file in arc catalog then pulling the file over to my map.
... View more