@arek2310: You need to enable Private Messaging. This is in the "Edit Options" of the control panel. If this isn't there, it has to be added somehow. You can try posting in
https://www.mobileread.com/forums/sh...d.php?t=319819 to ask it to be enabled, or contact a moderator.
But, weird screen glitches could be a damaged screen. If you search for them, you can see what they look like and compare them to your screen.