Are you trying to install the official SmartThings integration or are you trying to install @tonesto7 community version?
Just in case people missed it, Anthony wrote the official integration for Rachio and ST, which ST published officially. Rachio made some updates to the API which required some changes to the official ST integration however, official integrations have to go through a stricter process of approval as opposed to unofficial community SmartApps and Device Type Handlers and right now that strict process is taking a LONG time SO… Rachio allowed Anthony to release what WOULD be the official integration as an “unofficial community integration” so that we can get the updated code now as opposed to waiting for the official integration to be updated.
I had to delete all of my official integration and then installed the version being discussed here through @tonesto7’s absolutely amazing Community Installer with basically one click and some credentials.
If you are not using Anthony’s Community Installer, you really really really really really REALLY should be: