Looks like the base url doesn't include the subdirectory of your Elgg installation. It should ;)
I'll make an issue so I can look into this
Issue https://github.com/ColdTrick/newsletter/issues/59
If we fix this, it'll only every be for the newest release of Newsletter (for Elgg 4.3+)
I dare not upgrade to Elgg 4.3+ I have too many plugins working! :-)
Tx Jerome!
info@elgg.org
Security issues should be reported to security@elgg.org!
©2014 the Elgg Foundation
Elgg is a registered trademark of Thematic Networks.
Cover image by Raül Utrera is used under Creative Commons license.
Icons by Flaticon and FontAwesome.