Apparently, my customers do not have the WPF black screen bug (Video Rendering Issues for WPF Windows – Rick Strahl’s Web Log) but the solution is elegant enough to be noted.
With some video card/drivers, WPF’s main window (and more particularilly MahApps main window) can be completly black. This seems to be an hardware rendering problem. Good news, a per processs solution exist:
that can be set at startup to SoftwareOnly. Good to know!