You install the hotfix on the Mac where your Roon Server is installed, following the provided instructions here: Roon 2.0.39 is live! [Hotfix]
If the issue you experienced was actually the issue that is fixed by the hotfix, there is nothing else to do. The albums should be displayed again as usual.
Before I update iPhone app its screen would stay on when music was pkaying (unless I closed it). I liked that so I could easily see what was playing. Since the upgrade the screen goes off like any other app within 3 minutes? Any reason this is happening?