unable to load files for conversion

I’m a new user of SIRIL and run into a problem while trying the software version 1.4.2.:

I found a nice introduction for Seestar users: https://www.youtube.com/watch?v=EUEOUvnW038 from Chris Gray and tried to reproduce this on my Windows 11 Pro system. I get an error while trying to load .fits for conversion. Nothing happens when pushing the “add” button on the image

What do I overlook to fix this?

Thanks for suggestions.

The log:
Initializing FFTW multithreading support…
log: Welcome to siril 1.4.2 for windows (x86_64 ucrt64) - GUI
log: Supported file types: BMP images, PIC images (IRIS), PGM and PPM binary images, RAW images, FITS-CFA images, Films, SER sequences, TIFF images, XISF images, JPG images, JPEG XL images, PNG images, HEIF images, AVIF images.
log: Setting CWD (Current Working Directory) to ‘J:\Astrofotografie\Siril\Bewerking’
log: Parallel processing enabled: using 20 logical processors.
log: Color management active.
log: JPEG ICC profiles supported.
log: Preparing python virtual environment: C:\Users\Ton Lindemann\AppData\Local\siril\venv.
log: Checking the python module is up-to-date…
log: Python module is up-to-date
log: Checking SPCC mirrors…
Failed to execute child process (No such file or directory)
log: Default FITS extension is set to .fit
Entering wrapping_idle for function 00007ff703e53830
Entering wrapping_idle for function 00007ff703e53870
log: Searching for scripts in: “C:\Program Files\Siril\scripts”…
log: Loading script: Mono_Preprocessing.ssf
log: Loading script: OSC_Extract_Ha.ssf
log: Loading script: OSC_Extract_HaOIII.ssf
log: Loading script: OSC_Preprocessing.ssf
log: Loading script: OSC_Preprocessing_BayerDrizzle.ssf
log: Loading script: RGB_Composition.ssf
log: Loading script from repository: CosmicClarity_Denoise.py
log: Loading script from repository: CosmicClarity_Satellite.py
log: Loading script from repository: CosmicClarity_Sharpen.py
log: Loading script from repository: CosmicClarity_Superres.py
log: Loading script from repository: DSA-Seestar_Mosaic_Preprocessing.ssf
log: Loading script from repository: GraXpert-AI.py
log: Loading script from repository: Hubble_Palette_from_Dual-Band_OSC.py
log: Loading script from repository: OSC_Preprocessing_WithoutDBF.ssf
log: Loading script from repository: Satellite_Trail_Removal.py
log: Loading script from repository: Seestar_Preprocessing.ssf
log: Adding core script to menu: Siril_Catalog_Installer.py
log: Adding core script to menu: GPU_Manager.py
Last available version: 1.4.2
Entering wrapping_idle for function 00007ff703e303d0
log: Primary SPCC catalogue set to: https://gaia.wheep.co.uk (3 working mirrors available)
Entering wrapping_idle for function 00007ff703e2eb00
log: Gaia remote SPCC catalogue available, response 65 ms
log: Local SPCC database repository is up-to-date!
Entering wrapping_idle for function 00007ff703e303d0
log: Local scripts repository is up-to-date!
Entering wrapping_idle for function 00007ff703e53830

(siril.exe:22948): GLib-GIO-CRITICAL **: 15:17:17.684: GFileInfo created without standard::type

(siril.exe:22948): GLib-GIO-CRITICAL **: 15:17:17.684: file …/glib-2.86.2/gio/gfileinfo.c: line 1625 (g_file_info_get_file_type): should not be reached

(siril.exe:22948): GLib-GIO-CRITICAL **: 15:17:17.684: GFileInfo created without standard::type

(siril.exe:22948): GLib-GIO-CRITICAL **: 15:17:17.685: file …/glib-2.86.2/gio/gfileinfo.c: line 1625 (g_file_info_get_file_type): should not be reached