Donald Trump's campaign page mocks present Democratic presidential nominee Joe Biden.
The page says, it appears you are as lost as me, with a photo of former Vice President Joe Biden.

The 404 page appears when a user clicks donaldjtrump.com URL i.e incorrect shows a photo of confused Democratic nominee Joe Biden.
You can visit the 404 error page by yourself by clicking here.
The typical reson for an error 404 error is when a website content has been removed or moved to any other URL. There are also other many reasons why a 404 error page could appear. These include: The URL or the content such as files or images was either moved or deleted without adjusting any internal links accordingly.