Ok I tried again with Qt 5.9.5. Unfortunately i get another segfault:

[  176.513125] SVPManager[3695]: segfault at 8 ip 00007f1d16d64db9 sp 00007ffefdd94350 error 4 in libQt5Widgets.so.5.9.5[7f1d16bc9000+62d000]

It's also really irritating to me that only the SVPcode extension is affected.

I was able to use SVP fine without that plugin. As soon as it is installed it, the Manager doesn't start and dmesg gives me the following message:

[ 1401.340922] SVPManager[14907]: segfault at a ip 00007f55aebd79c9 sp 00007ffd0d480168 error 4 in libQt5Widgets.so.5.10.0[7f55aea55000+62b000]

I'm using KDE neon based on Ubuntu xenial. I've already tried other versions of the libQt5Widgets.so file.

I really cannot find a solution. Can anyone help me?

Thanks