Hello again.
As you might have heard, also the developers of Roundcube are just human beings and thus not always creating perfect and 100% bug free work. The last 0.4.1 release fixed many bugs but also introduced a quite annoying new one. That's why the next release follows just one week later. It fixes a few important bugs, especially the "Server Error" message when expanding/collapsing folders and it also updates some previously incomplete localization files.
Please replace your 0.4.1 or even 0.4 installations with this new version. It can be downloaded from http://roundcube.net/download. We also provide a patch for those who have local modifications and don't want to replace all the files again. See https://sourceforge.net/projects/roundcubemail/files/
Thanks for using Roundcube webmail!
~Thomas _______________________________________________ List info: http://lists.roundcube.net/users/ BT/9b404e9e