After creating a new draft newsletter, I click "Save" to save it. I get "There has been an error." If I enable dev mode, this translates to the following error. How can I fix it? It hasn't happened previously -- it's just started happening all of the sudden:

-------------------------------------------------------
ERROR:Error 256: Unknown Email ID: 40
At l443 in [...]code/NewsletterAdmin.php
user_error(Unknown Email ID: 40,256)
line 443 of NewsletterAdmin.php

NewsletterAdmin->getNewsletterEditForm(40)
line 230 of NewsletterAdmin.php

NewsletterAdmin->NewsletterEditForm()
line 214 of NewsletterAdmin.php

NewsletterAdmin->EditForm()
line 169 of Controller.php

Controller->run(Array)
line 104 of Director.php

Director::direct(admin/newsletter)
line 158 of main.php

I have the same issue. After saving my draft and then returning to edit it I get error loading.

user_error(Unknown Email ID: ,256) line 548 of NewsletterAdmin.php NewsletterAdmin->getNewsletterEditForm() line 143 of NewsletterAdmin.php NewsletterAdmin->shownewsletter(SS_HTTPRequest) line 193 of Controller.php Controller->handleAction(SS_HTTPRequest) line 143 of RequestHandler.php RequestHandler->handleRequest(SS_HTTPRequest) line 147 of Controller.php Controller->handleRequest(SS_HTTPRequest) line 282 of Director.php Director::handleRequest(SS_HTTPRequest,Session) line 125 of Director.php Director::direct(/admin/newsletter/shownewsletter/7) line 127 of main.php

Did you fix this??

EDIT

I solved my issue by reinstalling the module. Deleted newsletter then reuploaded a fresh download and now the error has stopped.