4 days ago, WordPress introduced a new version : 4.2 .
A tiny change in the taxonomy toolbox (support of parameter ‘name’ in get_terms() function) changed the behavior of MailPress when using Mailinglist add-on .
This impacts mostly dropdown lists where mailinglists are involved.
A fix currently under test is available in the WP plugin repository as the Development version.
It can also be downloaded at this link.
MailPress 5.4.2 should be available in a few days – as the current MailPress version – if no other bugs are reported.
Thank you for your support.