I don't know how, but the container under the center armrest has levitated and won't go down. On top of that, the armrest itself is open from the driver's side and won't close.

I think the second issue may be related to the first. So my first question is how to get the container back down?

 

I believe the second issue is actually the main issue
Here's a thread on that: https://mbworld.org/forums/c-class-w...opped-off.html

It's tricky, but after some fiddling you will be able to pop it back. Happened to me twice already...