AddType not respected by browser

**UPDATE** learning that application/javascript has been deprecated, this has now been updated to read: text/javascript. Issue persists. I have verified that this is not an actual 404. a file of that name exists at that path, with ownership and permissions which should make it accessible to the webserver user. Following Marcus Müller's suggestion below, that the AddType directives I added years ago to an apache2 virtual host template are now redundant, I commented those out, and ran a stop / start on apache and the php-fpm. I'm still seeing the same results in the network tab. ----- for a couple of years now, my apache2 virtual host containers include, in the top scope, unaffected by conditionals, these two lines: AddType text/css .css AddType application/javascript .js and there is this: $ apache2ctl -M | grep mime mime_module (shared) still the firefox network tab reports that multiple files are giving me 404s, and errors reading: NS_ERROR_CORRUPTED_CONTENT. Each is clearly identified with their .css or .js extensions and are all being seen in the browser as malformed html code. Any thoughts on how to further diagnose or resolve this issue would be greatly appreciated. -- Hugh Esco