Hi @panos.roussos Thanks for your question. You can download the package here. Unfortunately I think this might be the 32 bit version only - I am checking about the x64 version. This is an older API and is feature complete in that we will not be adding new features or capabilities to it.
We have a nicer experience for .NET users with our Refinitiv Data Platform and Refinitiv Data Platform Libraries (.NET (Alpha Release), TS/JS, Python). Under the hood the Refinitiv Data Platform uses standards based web technologies (eg websockets for streaming realtime / request-response for non-streaming) which play nice pretty much everywhere and which you can interact directly with but we have also added nice ease-of-use libraries (link above) which contain different abstraction layers for handling objects from high-level one line functions to lower level 'a few lines' of code to have total control over options etc.
Whilst the older library will work - I strongly urge you check out Refinitiv Data Platform libraries. For Eikon users any valid APP KEY will work. Please see the following two articles for further resources - Discover our Refinitiv Data Platform Library (part 1) and Discover our Refinitiv Data Platform Library(part 2)
I hope this can help.