exactly the same happened to me.Turned off and on all computers,routers,tp link,phome but can’t access open sprinkler.refresh doesn’t work,you don’t explain how to ensure no cache is being used.I had been using only the original interface as the mobile app style is too jumpy when field testing valves on manual but now even the the error page saying “unable to load UI is in the more modern style like the forum now is.What is the time frame to fix this? Also I use an older Ipad[5.1.1] for mobile control is this no longer supported? thanks rwp