This minor bug occurred only in 4.3.0.0 (for me at least).
Rostonix's solution worked for me: http://zennolab.com/discussion/showthread.php?7664-server-not-available-in-zennoposter-proxychecker&p=43839&viewfull=1#post43839
But I figured that I'd still report it as a bug so that we don't have to continue to do the temporary solution in future versions of Zennoposter MP.
Rostonix's solution worked for me: http://zennolab.com/discussion/showthread.php?7664-server-not-available-in-zennoposter-proxychecker&p=43839&viewfull=1#post43839
But I figured that I'd still report it as a bug so that we don't have to continue to do the temporary solution in future versions of Zennoposter MP.