Error Fill Sinks in Terrain Processing of Arc Hydro tools

[InshaBatool]

I am doing watershed delineation of DEM for my study and using arc hydro tools for that. When I apply fill sinks tool in terrain processing, it give an error. I already done with parallel processing 0 in the environment. But still catch up with that error. I attached files related to the error below. Can someone please help me out in it.

[DanPatterson]

The first error is because you didn't specify a file extension for the output raster since you were putting it in a folder.... try fil.tif

[InshaBatool]

My issue is resolved, thank you Patterson.