Do you mean the weaver menu option add logo to the left?
If so, try a different image in case the image file is corrupted.
Next, I would try to deactivate ALL non Weaver plugin and see if that fixes it. if so reactivate one by one
Also make sure you are not using any CSS / Js optimization plugin as these can break the site.
Last we would need a link to the page when you added the logo to check it out. But FIRST try the above