Plugin could not be activated because it triggered a fatal error

https://www.ads-software.com/support/topic/plugin-could-not-be-activated-because-it-triggered-a-fatal-error-50?replies=1

And many more lines. When I fixed all these, now I just get this:

https://www.ads-software.com/support/topic/you-are-not-allowed-to-edit-these-settings?replies=8

https://www.ads-software.com/extend/plugins/smallerik-file-browser/