File Upload is not working. Internet Sites document is already set to allow post/upload of a post this size. The Domino server console may report that cannot write to disk and may include the comment disk marked for read only. Verifying the server's rights to the domino and dominodata directory shows the server's account has write access to those folders.
Domino user did not have access to the /tmp partition. In windows, Domino needs write access to the temporary folder specified in the $Temp envirnmental variable(s).