Edit: I just googled your error and the same fix was in the first several results. I stopped looking after I saw that. Ummm did you even try googling the problem? You can try that fix or try and use iCleaner and toggle on "Cydia Sources". If you don't normally use iCleaner but you want to try this, method you could always toggle all the other options off and only have it run then"Cydia Sources" cleaning.