GDPR Compliance & Cookie Consent can’t be activated

Hi, I am using “Consulting/Child Theme” and it’s not possible to activate the GDPR Compliance & Cookie Consent Plugin. It causes a fatal error. All themes, plugins and wordpress are up to date and activated correctly. The php Version is 7.4. I am using Firefox on Mac. I tried to activate the plugin using Twenty Twenty-four theme but the same problem uccured. Can you please help?

Thank you. Kind regards.