I am trying ProgDVB 5.15.10. Unfortunately I have some problems selecting the used filters in "custom graph construction mode".

I try to select VMR-7 or VMR-9 as the video renderer on WinXp with DirectX 9.0c. Whatever I select as filter on the custom sheed or as Audio Settings output card, the File->Properties dialog always shows the following filters:

Audio render
Video_Renderer
Audio decoder AC3
Video decoder

The sound with AC3 is quite strange with my soundblaster X-Fi, just like using the wrong speakers are used.

When I select "video renderer", I get an error-msg to install elecard H.264/AVC or to use an other decoder, even if I selected something else. But as a strange result the File->Properties dialog shows the following filters:

Video_Renderer
Default_DirectSound_Device
CyberLink Video/SP Decoder (PDVD7)
InterVideo Audio Decoder

I can now change the corresponding properties and AC3 works well. Unfortunately, I get the mentioned error-msg every time, I change the channel. How can I select the given configuration correctly?

try start ProgDVB with /debug key for more information.

I tried to start the program with:
progdvbnet.exe /debug
from command line. I also tried some other params, but in all cases the program crashes while loading with the splash screen at approx. 75% of the progress bar. (Even, when I only pass a space) The command line works without arguments. What can I do?

It is too strange. Try install to empty folder without plugins.

I did a new install in a different folder now, but it shows the same strange behaviour. Are the any registry key, which can be deleted?

No. ProgDVB not use registry.

Make sure, the path to ProgDVB does not have any spaces inside, or else you may have to put the whole command line path into quotation marks, like
"C:\my special folder\ProgDVB\progdvbnet.exe" /debug
or even
"C:\my special folder\ProgDVB\progdvbnet.exe /debug"
And don't use Unicode file or folder names, stay with ASCII and your primary codepage.

Sometimes, also graphs or plugins may fail due to similar reasons. Worst case, if your user account and therefore personal folders include spaces.

Windows should always be able to handle this these days, but, in case of trouble, who's gonna tell it the truth...