About config

I read the strings of comments regarding about:config not working and presenting a blank page. I have the same issue. I have been a Firefox user for decades, preferring Firefox over all other browsers. However, without the ability to customize Firefox we, the loyal, may be forced to use another browser. Also, no customization is only contribution to other browser's owners/developers efforts to eliminate Firefox. Is there a solution to fixing current version or Firefox, about:config in development or already available?