As web browsers update they are becoming less friendly with common plugins used by many old educational resource websites, especially educational games and interactive media.
Plugins such as Flash, Java, Shockwave, etc. that in the past worked without you needing to do anything are now being blocked by web browsers. New web browsers are expecting websites to use new technology (html5) instead of plugins and are blocking them as a security risk.
What does this mean for old websites I’ve used?
All cases are different, test the website/resource first. Some plugins may be blocked completely depending on their age, others can still be enabled for you to use.