The Unreal Engine plugin for RealSense unfortunately stopped working properly from the R2 SDK onwards, and the author of the plugin said that they no longer had the free time to update it. R2 is fully compatible though with the Unity engine if it is possible for you to change engines for your project.
Thanks for the reply.
I don't think I'll be able to change to unity at this point.
Do you think i can get hold of the R1 sdk from somewhere?
Intel retired the R1 and earlier SDKs because of a potential security vulnerability, so it's extremely hard to find a working download link now. Only Chinese sites seem to still host it, and these sources are too risky to casually click on download links without knowing what you are downloading, so I do not know if the links work as advertised. If you want to research the topic yourself at your own risk, preferably from a reliable source, the R1 SDK (also known as R6) has the following filename:
Edit: I had an idea that may help you and keep you safe from risky sites if you really need Unreal Engine compatibility. Although SR300 camera support was not introduced til 2016 R1 (making it hard to use UE with RealSense due to this SDK being so hard to find), the fact you are using the R200 may give you a chance for success. This is because the Intel China servers (a very trustable source) still have a download for the old R2 2015 SDK, where R200 support was first introduced.