You should be more descriptive.
it is hard to give suggestions or help based on what you provided.
Where do you get this error or failure?
is it an app or is it part of the cpanel?
what is the page url ?
For error 503, x10hosting server is overload because someone on that server use a lot of server resources ( CPU and RAM) or your site is hogging a lot of that. Wait a while for a freed resource.
For error 404, check your coding since it work on localhost especially the URL of asset. For example like on pointing resource on x10hosting, you should use http://mysite.x10hosting.com/asset instead of http://localhost/asset.