On a PC - Press the CTRL, Shift, and R keys at the same time.
On a Mac - Press the Command, Shift, and R keys at the same time.
Some extensions cause issues and prevent ion from loading properly. Your district IT support will likely be able to assist you in resolving this issue.
At times, extensions such as PrivacyBadger and AdBlock Plus have caused issues. Configuring a site wide exemption is often way to keep the extension while also allowing ion to load properly.
Loading ion in an "incognito window" is another way to check if an extension is causing issues.