Viewer with annotations: Authentication Issue

Since a couple of weeks, I cannot use the beta viewer anymore. Whenever I open a PDF, I am spammed with messages that say “There was a problem with the authentication to our servers. If the issue persists, please contact us as at”

These keep popping up infinitely so it’s impossible to click them away and continue working. In fact, nothing on the UI is responsive as long as the messages stay on screen.