As of Firefox 62, the App Cache has been disabled for insecure sites, so this is now on the more urgent side:
https://www.fxsitecompat.com/en-CA/docs/2018/application-cache-can-no-longer-be-used-on-insecure-sites/
As of Firefox 62, the App Cache has been disabled for insecure sites, so this is now on the more urgent side:
https:/ /www.fxsitecomp at.com/ en-CA/docs/ 2018/applicatio n-cache- can-no- longer- be-used- on-insecure- sites/