I'm guessing you must have downloaded a sample using Eikon COM or .NET APIs and tried to run them on a machine that doesn't have Eikon installed. All Eikon APIs have a dependency on Eikon. In order to use Eikon APIs you need to have Eikon user account and you need to have Eikon installed.
@olatunji.ewebiyi could you specify which code sample for which api you are attempting to run please?