Solved! Go to Solution.
urgent! how did you resolve and restore the RasterEngine.dll issue?
I'm just now having similar frustrations with Spatial Analyst on V10.3 on a Windows 10 PC. Haven't previously had any regular crashes with ArcMap; I've been working through a certificate course in GIS.
Currently finding most processing works, but sometimes can't that far: when using extract by Attributes, I got a crash if I tried to save the expression (unless I did that before selecting the input raster). And now I get a crash as soon as I load the Raster Calculator.
RasterEngine.dll appears to be in a sensible location.