Since v11.5.4 DO crashes each 30 sec. after an update until I restart (happens on 2 PC's). Not that important, but never happened before.
Here's the message:
This could happen with any update. The installer doesn't say you need to reboot at the end just for fun. 
Because it never happened before I've always thought that I need to reboot to be able to use a new version (and double click on desktop feature, which always was gone immediately after upgrade).
Unpleasant surprise this time (11.5.3 -> 11.5.4).
We can make it always crash until you follow the installer's instructions and reboot, if you want.
Indeed, it would be some progress.
And probably easier to achieve than scheduling an update of program files to the next start of system. 
Nothing is easy with Installshield.
Bottom line is, don't install updates until you're ready to reboot, and reboot when the installer asks, else things won't work properly.
The Moon must be in the right phase for this subject to come up again.
For more enlightenment and entertainment, simply search this forum for Installshield.