That's either an add-on or a browser setting. Something you did yourself.
If you can't find out to unblock it, rest the browser (but you'll lose other settings then also), try another browser (Firefox, Chrome, Internet Explorer and Edge on Windows 10 are free) or use the same browser in a new Windows account.
When I open my Union Gas bill and go to my account page my gas usage is blank. There is usually a graph showing my gas usage but all that is there is a grey puzzle piece and a note saying " Adobe Flash Player is blocked. How do I fix this glitch? And that's not the only site I have problems with. I have tried to download Adobe after uninstalling it but the problem persists.

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic