Renaming a webform handler - old class stuck in DB despite clearing cache I'm creating a custom webform handler plugin based on the advice here, adding the class, in the correct directory, to an existing module.

I got the class name / some of the docblock info wrong initially - and need to change it.  Having run drush cr, the listing on  /admin/structure/webform/config/handlers seems to be stuck on the old entry.

I get "Cannot declare class ... because the name is already in use" errors when trying to add the handler to the form, for a class name that I'm no longer using, and which, having cleared the cache, definitely isn't in  cache_discovery.webform_handler_plugins in the DB.

I've also swapped browsers.  

What am I missing?
Sometimes, especially with a local dev environment, after you have tried every other route the only other avenue is to restart the PHP service and/or reboot the server/VM. This should clear system caches and often times will resolve this issue.