When you experience an issue that is isolated to your computer and the browser you are using, you may need to clear your browser cache. For example, if you recently updated the logo on your home page, and your colleague can see the change on their computer but you cannot, clearing your cache is a good first troubleshooting step.
The process for clearing your cache is different in every browser.
Here's documentation from all the major browsers on how to clear your cache:
Please note: after you've cleared your cache, be sure to completely restart your browser. This step ensures that the cache is completely cleared.