SUMMARY
***
NOTE: If you are reporting a crash, please try to attach a backtrace with debug symbols.
See https://community.kde.org/Guidelines_and_HOWTOs/Debugging/How_to_create_useful_crash_reports
***


STEPS TO REPRODUCE
1. open a project
2. try to render using h264_qsv (complete args attached below)

OBSERVED RESULT
crashes with
```
Qt: Session management error: Could not open network socket
[h264_qsv @ 0x7fc48c201e00] Error creating a MFX session: -9.
[subtitles @ 0x7fc485173340] libass wasn't built with ASS_FEATURE_WRAP_UNICODE support
```

EXPECTED RESULT
rendering should just work fine, all the intel drivers have been installed already

SOFTWARE/OS VERSIONS
Windows: 
macOS: 
Linux/KDE Plasma: Fedora 39 XFCE (Kernel v6.7.5-200.fc39.x86_64)
(available in About System)
KDE Plasma Version: 
KDE Frameworks Version: 6.0.0
Qt Version: 6.6.2

ADDITIONAL INFORMATION
vainfo:
```
Trying display: wayland
Trying display: x11
libva info: VA-API version 1.20.0
libva info: User environment variable requested driver 'iHD'
libva info: Trying to open /usr/lib64/dri/iHD_drv_video.so
libva info: Found init function __vaDriverInit_1_20
libva info: va_openDriver() returns 0
vainfo: VA-API version: 1.20 (libva 2.20.1)
vainfo: Driver version: Intel iHD driver for Intel(R) Gen Graphics - 23.4.3 ()
vainfo: Supported profile and entrypoints
      VAProfileNone                   :	VAEntrypointVideoProc
      VAProfileNone                   :	VAEntrypointStats
      VAProfileMPEG2Simple            :	VAEntrypointVLD
      VAProfileMPEG2Simple            :	VAEntrypointEncSlice
      VAProfileMPEG2Main              :	VAEntrypointVLD
      VAProfileMPEG2Main              :	VAEntrypointEncSlice
      VAProfileH264Main               :	VAEntrypointVLD
      VAProfileH264Main               :	VAEntrypointEncSlice
      VAProfileH264Main               :	VAEntrypointFEI
      VAProfileH264Main               :	VAEntrypointEncSliceLP
      VAProfileH264High               :	VAEntrypointVLD
      VAProfileH264High               :	VAEntrypointEncSlice
      VAProfileH264High               :	VAEntrypointFEI
      VAProfileH264High               :	VAEntrypointEncSliceLP
      VAProfileVC1Simple              :	VAEntrypointVLD
      VAProfileVC1Main                :	VAEntrypointVLD
      VAProfileVC1Advanced            :	VAEntrypointVLD
      VAProfileJPEGBaseline           :	VAEntrypointVLD
      VAProfileJPEGBaseline           :	VAEntrypointEncPicture
      VAProfileH264ConstrainedBaseline:	VAEntrypointVLD
      VAProfileH264ConstrainedBaseline:	VAEntrypointEncSlice
      VAProfileH264ConstrainedBaseline:	VAEntrypointFEI
      VAProfileH264ConstrainedBaseline:	VAEntrypointEncSliceLP
      VAProfileVP8Version0_3          :	VAEntrypointVLD
      VAProfileVP8Version0_3          :	VAEntrypointEncSlice
      VAProfileHEVCMain               :	VAEntrypointVLD
      VAProfileHEVCMain               :	VAEntrypointEncSlice
      VAProfileHEVCMain               :	VAEntrypointFEI
      VAProfileHEVCMain               :	VAEntrypointEncSliceLP
      VAProfileHEVCMain10             :	VAEntrypointVLD
      VAProfileHEVCMain10             :	VAEntrypointEncSlice
      VAProfileHEVCMain10             :	VAEntrypointEncSliceLP
      VAProfileVP9Profile0            :	VAEntrypointVLD
      VAProfileVP9Profile0            :	VAEntrypointEncSliceLP
      VAProfileVP9Profile1            :	VAEntrypointVLD
      VAProfileVP9Profile1            :	VAEntrypointEncSliceLP
      VAProfileVP9Profile2            :	VAEntrypointVLD
      VAProfileVP9Profile2            :	VAEntrypointEncSliceLP
      VAProfileVP9Profile3            :	VAEntrypointVLD
      VAProfileVP9Profile3            :	VAEntrypointEncSliceLP
      VAProfileHEVCMain422_10         :	VAEntrypointVLD
      VAProfileHEVCMain422_10         :	VAEntrypointEncSlice
      VAProfileHEVCMain444            :	VAEntrypointVLD
      VAProfileHEVCMain444            :	VAEntrypointEncSliceLP
      VAProfileHEVCMain444_10         :	VAEntrypointVLD
      VAProfileHEVCMain444_10         :	VAEntrypointEncSliceLP
```

rendering setting #1:
```
ab=0k acodec=aac bf=2 c:v=h264_qsv channels=2 f=mp4 g=15 hwaccel_device=/dev/dri/renderD128 movflags=+faststart preset=faster qscale=0 real_time=-1 threads=4 vb=16M vcodec=h264_qsv vf='format=nv12,hwupload'
```

rendering setting #2:
```
ab=256k acodec=aac bf=2 channels=2 cpu-used=4 f=mp4 g=15 preset=faster real_time=-1 threads=4 vb=9M vcodec=h264_qsv
```

both settings have parallel processing off
crash still happens with a project with no subtitles
that same project also rendered just fine on December of last year