Some add-on software (plugins, toolbars, and security programs) can alter a web browser’s ability to display and interact with websites, for example not loading the website correctly or causing a time out issue. Resetting a web browser can many times fix problems viewing a web page correctly.
Open Firefox and click the Firefox Menu, then click on Help or the Question Mark.
Then click Troubleshooting Information.
When this opens, click the button for Refresh or Reset Firefox.
After Firefox has reset itself, give it another try.