This is happening to me for a log time now. I have Zoom app installed and also Dropbox app installed. It used to work just fine but after one update, it started this glitch. I go to share then select Dropbox. That takes me to the screen sailor64 was showing. It just opens up the browser with the dropbox sign in page and then if I click to sign in, nothing happens. I'm wondering when this bug is going to be fixed. It's been too long like this and very incovenient.