You will want to make sure Java and Flash are up to date, these are pieces of software that are used by many applications online to function and display properly. they can be downloaded from these links.
go through the download instructions to install each of them.
when installing java be sure to uncheck the checkbox that says you also would like Ask, Ask is a browser redirector that can cause some issues
when installing flashplayer be sure to uncheck the checkbox that says you would also like to install Mcafee Security Scan Plus, this is essentially and advertisement for Mcafee that will cause popups on your computer.
if you are having trouble downloading refer to this Knowledge Base article: