You may need to clear your browser cache. Assuming you are using Chrome:
Press F12 to open the browser tools.
Click back into the main browser window displaying the Dataverse UI.
Right-click on the browser's page refresh icon
Click on the 'Empty Cache and Hard Reload' option.
Wait while the browser cache is cleared and the page reloaded (this may take some time).
When the page has refreshed, click the 'X' close icon on the browser tools panel on the right hand side.