It seems that you are using a very old version of X and Cornerstone. In that case you will have to manually update X through FTP then validate it.
Here is a link for a details information on how to do an update:
Please remember to clear all caches when updating so that the code from the latest release is always in use. This will help you to avoid any potential errors or any unexpected display issue on the site.
As for the issue with the media upload, just like what @mldarshana, you will have to check the permissions of your folders. If you are not sure how to proceed, kindly get in touch with your hosting provider so that they can help you sort it out.
Hope this helps.