Firefox Personas preview not working

If you find that when you hover your cursor over a persona and find the preview not working, check that you have Java enabled in Plugins under Add-ons Manager. If you have Java enabled but still cannot preview a persona, add this URL https://www.getpersonas.com/en-US/ to the Exceptions list > Tools > Options > Security > click the Exceptions button next to Warn me when sites try to install add-ons. You should be able to preview personas now.