First time user here so please be gentle!
I installed Grav (with Admin) from the zip and it appears to work perfectly.
Until I try to install a theme. Then I get the above error. The problem is that according to phpinfo the feature described in the help documents is installed and enabled already.
So why the error and how do I fix it?
This is what phpinfo shows for zip
|Libzip headers version||1.6.1|
|Libzip library version||1.6.1|
Any assistance gratefully received.