Besides the fact that the link is broken, this thread is for EasyPopulate v4 not version 3.0.3. An upload issue such as described is likely to be resolved by splitting your file so that it is smller or as suggested by the error message increasing the maximum upload file size.

Otherwise don't know what thread to access for EasyPopulate v 3.0.3, but if you go to the first post of this thread you can download EasyPopulate v 4.