flow direction (spatial analyst) tool error

[Md__Rakib_Hossain]

I have enabled all the extensions in the customize toolbar including spatial analyst tool. But whenever I run this Flow Direction tool formy DEM, Flow Direction tool shows some error. Please see the attached screenshots for the input and error messages. Please HELP.  

[DanPatterson]

What is this about image server not having the right license?

Do you have licenses requiring server access?

If you aren't working with a local install, you will have to check on that end

[Md__Rakib_Hossain]

Dan, Thanks for your reply.

But my ArcGIS v10.8 is licensed. Is license requiring server access differs from the ArcGIS license? If yes, then how may I get it?