Activation issues

I have installed the plugin but when I try to activate it, I get the message: “Sorry, you are not allowed to access this page.”

My woocommerce and wordpress sites are up to date, I have disabled the ad blocker on the browser and my website is whitelisted on my firewall.

I have also checked my cache plugin settings- I do not have html javascript minified, but have css minified.

Any ideas as to what is blocking the plugin please? I have a Caching plugin with some basic scripts cached/minified and a Firewall with basic protection.

Thanks