So I saved a head as a .png, tried converting it to a .jpeg and loading the head onto my texture item still pops up as:

"Upload failed. Make sure the filetype is valid
Contact support for more information."

What's going on here

Make sure you are uploading the texture on http://forum.toribash.com/tori_textures.php and that you did not change the file extension by just changing it's name. Also, try to upload your texture using each of these extensions: