Windows: QtCreator 4.5 against Qt 5.10b2: Frequent crashes when using -client

With Qt Creator 4.5 at 6138bc3d41cde525f2c0f3fed806ad2b3d387f63 , Qt 5.10 at qtbase: f174d31667dca184439f520b9624a1471d9556a6 , Qt Creator frequently crashes when using the -client option.

Steps to reproduce:

• Launch one Creator
• Open a file using another instance: qtcreator -client foo.cpp

The QtSingleApplication examples do not seem to reproduce it.
So, it could be sth in Creator or related to "Support more than 62 instances of QWinEventNotifier, take 2" 85403d0af06a0728c9c6f1bd7a6f224949cd894e https://codereview.qt-project.org/#/c/200998/ (which introduced the crashing wfsoCallback()).