Ran into this today, thought I better make myself a note. By default PHP sets a limit on the size of a file that can be uploaded; yeah, great, you’ll find how to change that limit on google.

But what doesn’t get mentioned very often, is that for uploading through the wordpress admin page, there is also another limit that needs to be changed.

Both: post_max_size and upload_max_filesize need to be changed. My default PHP install had post max size set to 18M and upload max size set to 2M.