I use vMix on a Win10 desktop and use a laptop with Win7 for PowerPoint. On the laptop I use Desktop Capture.
I recently upgraded vMix to version 23 and I also upgraded the laptop to version 23 also. Now when I start
the Desktop Capture on the Win7 laptop, I get an error message:

System.AccessViolationException: Attempted to read or write protected memory. This is often an indication that other memory is corrupt.
at vMixDesktopCaptureLibrary.NDISendWin32.NDIlib_send_send_video(IntPtr p_instance, NDIlib_video_frame_v2_t& p_video_data)
at vMixDesktopCaptureLibrary.NDISendBase.SendVideo(IntPtr p, Size sz, Int32 stride, Int64 timestamp)
at vMixDesktopCaptureLibrary.DesktopCaptureServer._CaptureThread()

Anybody know what the error message means? Or better yet, what is the fix? Maybe upgrade the laptop using Win10?

I guess for now, I will go back to vMix 22 on both machines.

Hi Johnny,

It looks like the Windows 7 install is most likely out of date and missing Windows 7 SP1 and/or the latest updates.
You can try downloading SP1 here:

https://support.microsof...stall-service-pack-1-sp1

After that go to Windows Update and check for and install the latest updates.

Regards,

Martin
vMix

hi martin,
just installed ver 23 and desktop capture is updated to 23 but when you start is it comes with an update message to 23.2... and that you have to do manually.

is this going tobe included in the update as well...

i now downloaded desktop capture from site and just replaced the files in the vmix folder. is that the correct way?

Stefan

Johnny,

Did you try the 23.2 update I posted above?

Just to double check and confirm, you have tried the 23.2 update just released on the system
and it is still showing the same error?

If so can you send a screenshot so we can investigate further?

info@vmix.com.au

Thanks,

Martin
vMix

To be fair, this sort of complaint completely without merit. You don't provide enough detail to make any kind of informed reply possible. Without the specs of the system, no one can offer any meaningful guidance.

Lacking for context, you offer zero insight as to why it happens. It's just not helpful.

Hi,
I yesterday encountered very similar behaviour on two machines.
Hardware not new, but SSSE3 capable Intels and latest Win10 2004 with all updates.

Machine one had running 23.0.0.38 and NDI Tools 3.8. smoothly.
I upgraded to 23.0.0.62 and NDI tools 4.5,
then
1/ vMix starts, but after few seconds closes/crashes.
2/ Desktop capture 23.0.0.4 or 23.0.0.5 ends with error - same as with the first post.
3/ Scan converter crashes too.

I reverted back to NDI 3.8 and 22.0.0.57 (because could not find 23.0.0.38 install exe)
and everything is running smooth.

The second computer was unable to run Desktop capture 23.0.0.4 (same error),
while vMix 23.0.0.62 was running OK.
After above experience I tried Desktop Capture 19.0.0.3 which is running smoothly.

The crash reports problem with an image being sent to NDI sending engine,
being at illegal address,
something that is very weird to be changed between versions (I did some NDI programming using NDI SDK)

If anyone is interested to investigate,
why older versions work, while newer die, let me know.

Karel