Your recent update for Minecraft messed up my launcher and I can't play

My Minecraft on Windows 10 triggered for an update. So I clicked on update and let it  update my Minecraft but now there is no sign in or world to click there is only the background. It was showing this symbol in very tiny print " ---<" and still does even after a reset of the app.

HELP!

My family and I play this together.

Many thanks for your time and efforts.

Gwen