Slope Function keeps failing

Question

Hello all,

I am trying to run the Slope tool on a DEM mosaic I have.  The original DEMs came from USGS and are in NAD UTM 1983. I have mosaiced them into a single dataset. I repeatedly get the dreaded Error 999999 when I run the Slope tool, but no messages indicating why. It fails as soon as it starts, even though my computer usually takes several moments to run a tool. Can anyone think of anything else I might be doing wrong here to cause the error?

DanPatterson_Retired · Answer

Go to know... now switch to ArcGIS Pro and you won't have to worry about 64bit

NicoleKeller · Answer

Thanks for replying, Dan.  Turns out, I just had to turn off background processing! I read in an article that can sometimes cause those spontaneous 999999 errors, and once I turned that off, my computer had no problem. SO WEIRD.

DanPatterson_Retired · Answer

are you using the raster function? or the raster tool in arctoolbox

Slope function—ArcGIS Pro | ArcGIS Desktop

Raster functions can be applied to mosaic datasets

Raster functions—ArcGIS Pro | ArcGIS Desktop  see the section

Functions can be applied to the following data types: