A user has reported getting errors from the Pebble web site while installing the Pebble App to connect the watch to the phone.
You seem to get this screen when you are creating a Pebble account as part of the set-up process.
Despite the error you can go back to the Pebble App and finish the set-up ok (it will update the watch firmware etc.), and OpenSeizureDetector will work ok.
So, although we get an error, it still works – OpenSeizureDetector does not need the Pebble web site once the watch has been connected to the phone ok.