Did you have a look at the number of rows and columns you were trying to process? and the cell size?
You aren't going to get it to process, you are running out of memory probably.
Try it without background processing.
Save the file to a local disk and don't try to run from some network location.
Simplify your raster. You certainly don't need 25 cm resolution, especially if you are contouring. So Resample it.
Try again, if that doesn't work, Resample or Tile the inputs. Get it to work at some scale, then play around with methods of getting a finer resolution if that is critical.