I waited a couple days for an answer to my question about loading the May 18 version and you replied just now wanting to know what version of Rhino I am using. I tried to respond only to find you had closed the topic! What is up with that. How about just posting a link to the download and I'll try again to install on Rhino V5.
Apologies for the confusion. I closed the thread because it was getting too long to be useful (as stated in the closing message). The rhino 5 x64 and 32bit version at http://food4rhino.com/project/iris seems to be working as expected. Download the rhi and double click to install.
Let me know where you are getting an error.