msafd related, Mozilla Thunderbird 52.9.1 does never start up (after TB45.8.0 has been updated via About tab)

0.4.11-RC-36-gc5204e3 gcc dbg linux.

Reproduction steps
-Install Mozilla Thunderbird 45.8.0 from rapps
-start the app, it will show its GUI successfully
-select the about tab to make it update itself to newest version
-(on 2019-02-24 this led to download and install of v52.9.1)
-when it asks for confirmation, let it restart Thunderbird

Expected result
The new version does start up and shows its GUI.
xpsp3_ok_showsTheGUI.webm manages the upgrade properly.
(beside a single one time msgbox about problems with the plugin directory, that does not longer show upon consecutive runs)

Observed result
It tries to start the new version thunderbird.exe, but will never succeed to show its GUI. It will not show any errorbox itself.
After a while of activity the new process thunderbird.exe hangs in taskmgr without any CPU usage anymore.
[^0.4.11-RC-36-gc5204e3__TB45_8_0_to_TB52_9_1.webm]
0.4.11-RC-36-gc5204e3__TB45_8_0_to_TB52_9_1.log

Some minutes later the Mozilla crashreporter.exe will show up (and Thunderbird.exe is gone from taskmgr).
crashreporter.png