I am trying to use Send to Blog for Drupal. After trying instructions:

both here: http://www.diigo.com/help/blog/3

and here: http://groups.diigo.com/group/Diigo_HQ/content/posting-to-a-drupal-blog-1249580

I am still seeing the error message "Sorry, server error. [1503]"

Searching "1503" in the Diigo Community produces many posts with people experiencing this error but no resolution. Can anyone help?

It's worth noting that we are working in a development environment on a subomdain, i.e. dev.domain.com, also that "Go to admin/settings/blogapi, select the Metaweblog type" no longer appears in the Drupal interface.