If you are encountering this error message after filling out the form on your MLSP™ Lead Capture page, you have not provided us with your correct autoresponder list name or Unique ID
Please double-check the information listed under 'Account' > 'My Autoresponders', and make sure the list name/unique ID there matches the campaign list name you created in your autoresponder program (GVO, Oprius, GetResponse or AWeber). If there's any differences between the two (which is what caused that error screen to appear), MLSP™ won't be able to forward your lead information to your mailing list.
As always, be sure to clear your browser cache and cookies (temporary internet files) before testing your corrected page.
Please note: Aweber - use unique ID listed under the list name in your Aweber account