@frustratedwriter I have Roku also, in fact that is the only way I watch Viki dramas I have had it for years. Here a few tips first even if you sign out of here on Viki web site. You will still be log in on Roku for Viki. What's important is DO NOT log out on Viki on Roku, otherwise you will have to logged back in and use a code that Roku give you, then you will have to come back on Viki web site to put in the code given you for Viki Roku app here on this site.
So It is best to just stay log in on Viki on Roku,I always stay log in, sometime you may have to for some reason logged out if so just follow just the same steps as I mention above. I only come here on the web site to see what new and add to my follow list that list also will be on your Viki on Roku it's really a nice set up. And if you have a Viki Pass you get NO ads.
Also be sure on your Roku that your particular caption language is set up. I love Using Roku, So to make it easy once you log into Viki On Roku just stay log in, once gain if you log out on Roku for viki you will need to do the steps I said. I am thinking you already found and setup Viki app on your TV. Anymore question just ask me