Cant render long video on Vegas Pro 23 - crash at 100% mc_mux_mp4.dll

Diego-Rodriguez9543 wrote on 3/6/2026, 3:17 AM

I bought Vegas 23 so I can use my GPU to render so my CPU doesnt reach high temperatures. Since NVENC doesnt work anymore on older versions of vegas I bought the new one.

However I cannot render long videos. I had success with a roughly 1 hour video. however for a roughly 11 hour video when it reaches 100% Vegas crashes and I get the below error report.

 

Windows 11 25H2

RTX 4090

 

Problem Description
   Application Name:    VEGAS Pro
   Application Version: Version 23.0 (Build 302)
   Problem:             Unmanaged Exception (0xc0000005)
   Fault Module:        C:\Program Files\VEGAS\VEGAS Pro 23.0\FileIO Plug-Ins\mcaacplug\mc_cpu\mc_mux_mp4.dll
   Fault Address:       0x00007FFF04F27BEE
   Fault Offset:        0x0000000000147BEE

Fault Process Details
   Process Path:        C:\Program Files\VEGAS\VEGAS Pro 23.0\vegas230.exe
   Process Version:     Version 23.0 (Build 302)
   Process Description: VEGAS Pro

 

I saw one other thread with this issue that recommended having more than 2x the hardrive space for both the C drive and the destination drive which I do. I am out of ideas as of now I can't even use the software for what I need it for.

Comments

3POINT wrote on 3/6/2026, 3:23 AM

Seriously, who watches an 11 hour video? Render your video in subsections and merge those afterwards to an 11 hour video with free Shutterencoder.

Diego-Rodriguez9543 wrote on 3/6/2026, 3:34 AM

Seriously, who watches an 11 hour video? Render your video in subsections and merge those afterwards to an 11 hour video with free Shutterencoder.

would be sad to pay this much for vegas to have to do that entire extra step. It worked before on older vegas versions until NVENC stopped working, literally the only reason i got vegas pro 23.

3POINT wrote on 3/6/2026, 5:11 AM

Return to previous NVIDIA driver and NVENC rendertemplates will work again in previous Vegaspro versions. Has been said a lot here in the forum about this. You are probably editing gamecaptures and not camera footage.