This message was triggered by WordPress Core.

Hi,

What does the message in Greek say?

Hi.

It’s not Greek language.

Hi,

You do not have the necessary rights to access this page.

No we don’t as this is in your Wp-admin dashboard. What does the error say in English?

That’s what the error says “You do not have the necessary rights to access this page.”

Can you try to re-install the plugin by an admin user?