Created attachment 120862 [details]
STEPS TO REPRODUCE
1. Open Kmail (or kaddressbook or korganizer)
2. Try to add a new account (or new addressbook or calender)
3. Choose EWS
The window is closed.
Open a new windows with options to add the new account
(available in About System)
Operating System: Arch Linux
KDE Plasma Version: 5.16.0
KDE Frameworks Version: 5.59.0
Qt Version: 5.12.3
Kernel Version: 5.1.9-arch1-1-ARCH
Very same behavior here, also with arch linux and with the same versions like OP.
Do you have the necessary optional dependencies installed?
I have installed kdepim-addons (optional).
I don't know if it is necessary other packages
> pacman -Qi kdepim-runtime
Optional Deps : qca: EWS resource
qt5-networkauth: EWS resource
I had installed qca but not qt5-networkauth.
I had checked dependencies before I reported the bug, but I hadn't do well.
Thanks and sorry
Also here, after adding the dependency qt5-networkauth, the wizard appears. It doesn't work but that issue is not related to this one.