Raptor: Call of the Shadows (1994 Classic Edition) 358360 (windows dosbox)

Compatibility Report

• Name of the game with compatibility issues: Raptor: Call of the Shadows (1994 Classic Edition)
• Steam AppID of the game: 358360

System Information

• GPU: 5700XT
• Driver/LLVM version: Mesa 21.1.5/LLVM 12.0.1
• Kernel version: 5.13.2-1-default
• Link to full system information report as Gist: https://gist.githubusercontent.com/zaggynl/3e3c17be865ac38c4fb5bc217e187403/raw/45fd8cb04864919fce02e0186b8b06c1943f2075/gistfile1.txt
• Proton version: 6.3-5, 5-13.6, 5.0-10

I confirm:

• that I haven't found an existing compatibility report for this game.
• that I have checked whether there are updates for my system available.

steam-358360.log
If I start steam from commandline I notice the below lines:

[0725/212936.309853:ERROR:frame_sink_video_capturer_impl.cc(206)] Invalid resolutions constraints: 0x0 must not be greater than 0x0; and also within media::limits.


[0725/212936.325238:ERROR:frame_sink_video_capturer_impl.cc(206)] Invalid resolutions constraints: 0x0 must not be greater than 0x0; and also within media::limits.

Symptoms

Dosbox starts but only shows a blinking black screen, no text in dosbox.
Short recording showing this:

Reproduction

Install raptor, start raptor through proton as for some reason it's not using linux dosbox, dosbox starts but only shows a blinking black screen.

Likely an issue with the videoplayer? Searching on the error messages shows some workarounds by removing video files, not sure how for raptor as video files seem to be packed.
Tried disabling Steam overlay.
Tried the suggestions to the conf file in: https://steamcommunity.com/sharedfiles/filedetails/?id=701564226

Start by reproducing the blinking black screen with Raptor through Proton using the reported Proton versions, then inspect steam-358360.log alongside the DOSBox startup behavior. The report mentions packed video files and Steam overlay settings as possible leads. Done means identifying a reproducible cause and confirming that the game reaches usable output without the blinking black screen.