I often get the following assert (debug build master) when I enter some letter into the folder tree view filter field. Although I can not forcibly reproduce it. ASSERT: "!storageModelId.isEmpty()" in file /home/KDE5/source/kde/pim/messagelib/messagelist/src/core/storagemodelbase.cpp, line 58
*** This bug has been marked as a duplicate of bug 378944 ***