Could not display interface. Please check definition and inputs.Interface Definition: Expression evaluation error in rule 'elm_qe_getemployeedetails' at function a!queryEntity [line 2]: The data store entity does not exist, has been deleted,

OK. Did you try to follow the tips in the error message?

By the way, if you describe what you are doing instead of just posting an error message, the community will see that as an expression of courtesy and be much more likely to be able and willing to help.

codeblog.jonskeet.uk/.../

As the error suggests, it is not able to find the DS. It may be because of the access or it might not exists.
Check for the mapping in the constant and then try re-publishing the datstore.