Command+C (copy) not working in Finder (Sierra) I just update from El Capitan to Sierra on my iMac, and the Cmd+C shortcut stopped working in Finder.

This means I cannot copy files nor filenames.

I tried both Cmd keys, neither works.

Command+V works, and copying via mouse (right click, select copy) works.

It all worked perfectly up until yesterday, before the upgrade!

I already rebooted my iMac.

Any ideas?
The problem was in Office: mac 2011. 
Total shut-down and switch-on TWICE solved the problem.