Big file upload unsuccessful

What are the upload limits of your host?

You might need to increase via a server setting in the php.ini

With shared hosting, upload limits are usually quite low.

E.g.

Try increasing the following values in php.ini, for example:

memory_limit = 32M
upload_max_filesize = 24M
post_max_size = 32M

But check with your host's wiki on how to proceed (it varies from host to host...)

E.g. with Dreamhost: