Make sure your Public Profile is set up. Go to Settings > Account to see your profile or set it up.

Note: if the profile doesn't save, please pick another username.

When submitting your Mashup, please make sure to use the submit button at the top right corner of the studio.

If you still get an error message after clicking submit, please take the following steps:

Go to the project menu > Save As > give the mashup a slightly different name (ex., add V2 to the name) - This creates an exact copy of your current mix. Then submit that version.