segfault at 8 ip 00007fe4fd9cc40f sp 00007ffc6d6d36a0 error 4 in libQt5XcbQpa.so.5.10.0[7fe4fd990000+15c000]

I can't run multiple software...

tested with:
qv4l2
gqrx
octave

All the same error:

Dez 15 18:01:12 fwalder-pc kernel: qv4l2[3545]: segfault at 8 ip 00007fe4fd9cc40f sp 00007ffc6d6d36a0 error 4 in libQt5XcbQpa.so.5.10.0[7fe4fd990000+15c000]
Dez 15 18:01:12 fwalder-pc systemd[1]: Started Process Core Dump (PID 3547/UID 0).
Dez 15 18:01:12 fwalder-pc systemd-coredump[3548]: Process 3545 (qv4l2) of user 1000 dumped core.
                                                   
                                                   Stack trace of thread 3545:
                                                   #0  0x00007fe4fd9cc40f _ZN14QXcbConnection10internAtomEPKc (libQt5XcbQpa.so.5)
                                                   #1  0x00007fe4fd9e0ba4 _ZNK10QXcbScreen7getEdidEv (libQt5XcbQpa.so.5)
                                                   #2  0x00007fe4fd9e24b7 _ZN10QXcbScreenC2EP14QXcbConnectionP18QXcbVirtualDesktopjP33xcb_randr_get_output_info_reply_tPK26xcb_xinerama_screen_info_ti (libQt5XcbQpa.so.5)
                                                   #3  0x00007fe4fd9d0df9 _ZN14QXcbConnection17initializeScreensEv (libQt5XcbQpa.so.5)
                                                   #4  0x00007fe4fd9d1775 _ZN14QXcbConnectionC2EP19QXcbNativeInterfacebjPKc (libQt5XcbQpa.so.5)
                                                   #5  0x00007fe4fd9d5590 _ZN15QXcbIntegrationC1ERK11QStringListRiPPc (libQt5XcbQpa.so.5)
                                                   #6  0x00007fe4fdcf919e n/a (libqxcb.so)
                                                   #7  0x00007fe5060c7a30 ZN27QPlatformIntegrationFactory6createERK7QStringRK11QStringListRiPPcS2 (libQt5Gui.so.5)
                                                   #8  0x00007fe5060d8810 _ZN22QGuiApplicationPrivate25createPlatformIntegrationEv (libQt5Gui.so.5)
                                                   #9  0x00007fe5060d934e _ZN22QGuiApplicationPrivate21createEventDispatcherEv (libQt5Gui.so.5)
                                                   #10 0x00007fe505b738d5 _ZN23QCoreApplicationPrivate4initEv (libQt5Core.so.5)
                                                   #11 0x00007fe5060dae20 _ZN22QGuiApplicationPrivate4initEv (libQt5Gui.so.5)
                                                   #12 0x00007fe5068eec6a _ZN19QApplicationPrivate4initEv (libQt5Widgets.so.5)
                                                   #13 0x000000000040f4f2 n/a (qv4l2)
                                                   #14 0x00007fe504018f4a __libc_start_main (libc.so.6)
                                                   #15 0x00000000004104aa n/a (qv4l2)
                                                   
                                                   Stack trace of thread 3546:
                                                   #0  0x00007fe5040e3f2b __poll (libc.so.6)
                                                   #1  0x00007fe4fe92c8e0 n/a (libxcb.so.1)
                                                   #2  0x00007fe4fe92e679 xcb_wait_for_event (libxcb.so.1)
                                                   #3  0x00007fe4fd9cd7aa n/a (libQt5XcbQpa.so.5)
                                                   #4  0x00007fe50597fb2d n/a (libQt5Core.so.5)
                                                   #5  0x00007fe5043b708a start_thread (libpthread.so.0)
                                                   #6  0x00007fe5040ee42f __clone (libc.so.6)