Ensure that Flash Player is enabled.
Click the "..." button to access the Edge menu.
Select the Settings menu item.
Scroll down to the Advanced Settings section and click the View advanced settings button.
Locate the Use Adobe Flash Player section and toggle the switch on to enable Adobe Flash Player.
Refresh your web page or open a new browser tab.
In the address bar, type chrome://settings/content.
On the Content settings screen, find the Flash Player listing. Check the status.
Select Allow sites to run Flash, and then click Done.
On the Flash exceptions screen, enter the website domain and then choose Allow. When finished adding sites, click Done.
Choose Firefox > Tools > Add-ons.
In the list of Add-ons, look for Shockwave Flash (another name for Flash Player) and check the status that appears to the right of the plug-in name.
(Citation: from Adobe.com help pages)