Dimmed for me too yesterday.. Went back to normal in 2-3 minutes. And reinstall is not a problem.. You don't lose your messages.
Nothing happen with it on my phone !
Reinstalled and WhatsApp works but all my chats gone. I do have a backup but it isn't picking and restoring, I don't know why. Should I keep it main memory for that to happen?Yeah.. You may lose some which haven't been backed up.. WhatsApp does it periodically.. Shouldn't be a problem.. Go ahead..