thanks, it is working now, I managed to successfully upload the zip file.

However I still got an error when I tried to submit a screenshot jpg along with the file so there seems to be a further bug

yes indeed I am trying to add my new theme to the library of themes on this site for sharing

NOT trying to install it on my own site, nor have I confused it with a template

As I said, when I log into my user account on this site, go to the themes library page and click on the link 'add the latest version of your own theme to the libray', fill in the online form, which includes the file upload, I get the error

"MIME-type not allowed: application/zip"

It is a perfectly ordinary zip file (created using winzip)

This seems to me like something is going wrong with your file upload script.

I am trying to upload my new theme to the themes library.

It is a zip file created by winzip. Each time I try I get the error message

"MIME-type not allowed: application/zip"

What is going on? Most of the themes in your library seem to be zip files, so why can't I upload it?