I used that until it was obsoleted with the new way Safari handles extensions, moving to AdGuard around 2016. Never looked back. uBlock Origin has always been nice. I used it in Windows until this year (switching to AdGuard there, too). But if it no longer does the job you need, it’s time to switch.
Just use a better ad blocker. AdGuard hasn’t thrown up this error for me in over a year.
I used that until it was obsoleted with the new way Safari handles extensions, moving to AdGuard around 2016. Never looked back. uBlock Origin has always been nice. I used it in Windows until this year (switching to AdGuard there, too). But if it no longer does the job you need, it’s time to switch.