Grey Rests

I see random grey rests in write mode (see attachment) after I upgraded to MacOS High Sierra 10.13.1.
Any ideas? Many thanks, and happy holidays to all.
Screen Shot 2017-12-22 at 15.27.40.png

Take a look in the menu View / Note and Rest Colors and see if the Implicit Rests item is checked. If so, uncheck it.

Implicit rests are created automatically, and this option allows you to spot them at a glance, drawing in grey, but not printing as such.

[SOLVED] Many thanks Stefan. Implicit Rests unchecked and problem solved.