A few minutes ago I was taking care of my inventory and suddenly my sidebar just disappeared, now I can't see my profile or notifications or anything. What do I do? Did I press a button that caused it or is someone else with the same problem?

search for a button on the top of the screen - maybe after the clock but before the menu, that says "toggle sidebar"

thank you! I have no idea how I pressed that by accident, but it worked!

You're welcome.

If you want you can use custom CSS to remove the button completely so you can't toggle it accidentally.

/* remove toggle sidebar button */ -toggle-button { display:none; }