Hi mtanquerel,

Does it got problem with all files? Or just large file?

Try create an folder name “mytemp” under your site root and set it for property “TempDirectory”. Give the full permission to user “Everyone” of this folder to test it again.

<CuteWebUI:Uploader runat="server" ID="uploader1" TempDirectory="~/mytemp">

</CuteWebUI:Uploader>

By the way, is your site under load balancing/web farm/cloud environment?

Regards,

Ken