Lost ability to rename folders on my notebook

Hi I have been doing some file sharing with my MacBook and IMac today and have now lost the ability to change folder names in Finder on my notebook - it's like I have lost permission. I have tried clicking slowly twice/click and return/click and command I and none of these are allowing me to change the folder names.

Any suggestions please? I am trying to align the folder names across my Macs so this is very frustrating!