I seem to have Foundry installed into RW 8, but how do I get it to show up? Do I have to install the Foundry theme? When I try to reinstall it it says its already installed - but it does not show as available anywhere (in the Themes menu - All Themes selected).
You also need as you pointed out, the Foundry Theme that you can find here: Foundry Release Notes also take a look on how to install Foundry in the support videos section here: Learning Center: Foundry Tutorial Videos and follow the instructions on the video on the “Install Foundry”.
Good afternoon @Adran and welcome to the community!
It sounds to me like you might have two version of RapidWeaver installed on your Mac. If so it could be that your theme got loaded by RapidWeaver into a different version of the app. The best thing to do is to drag and drop the theme and stack onto the RapidWeaver icon in your computer’s Dock. This indicates to the version of the app you wish to make sure the plugins get installed into.
As @egomade mentioned, there is a video tutorial on the Foundry Documentation page that walks you through installing the Foundry theme and stack, along with a plethora of other great tutorials.