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PeterCJ
PeterCJ
Participant
March 27, 2026
Question

LrC 15.2.1: dynamiclinkmediaserver crashes in mc_mfimport when importing 10-bit HEVC video from Sony a7RV on MacBook with M4 Max

  • March 27, 2026
  • 1 reply
  • 47 views

Lightroom Classic 15.2.1 fails to import video files from my Sony a7RV (4K 10-bit HEVC 23.98fps 50Mbps) on my MacBook Pro 14” with M4 Max. The background process dynamiclinkmediaserver (version 24.0.0) crashes immediately upon probing the file, causing an "RPC connection terminated" error (-10001) in the Lightroom output (when I run LrC from Terminal).

System environment:

  • Lightroom Classic Version: 15.2.1 (though this has been happening for me since the end of December 2025 using whatever was the latest LrC version at the time)
  • OS: macOS 15.7.4 (Sequoia)
  • Hardware: MacBook Pro 14", Nov 2024 (Mac16,6) with Apple M4 Max chip
  • Camera: Sony a7RV, 3840x2160, 23.98 fps, 10-bit HEVC, 50 Mbps.

Steps to reproduce:

  • In LrC, choose File → Import Photos and Video…
  • Select a source folder containing video .MP4 files with the characteristics described above.
  • With at least one such video checked, click “Import”.

Expected result:

  • Selected video files are added to the LrC catalog and copied to the specified destination (assuming “Copy” was selected).

Actual result:

  • Popup error like this, showing all the affected video files:
  • After this occurs, similar videos already in the LrC catalog fail to play in the Library view, with a message at the top saying, “There was an error working with the video”; this playback problem persists until restarting LrC.

Additional diagnostic notes:

  • As soon as the folder with the affected videos is selected in the Import panel, and it tries to render previews of them, if LrC was launched from a Terminal command line, a whole bunch of lines like the following are output, with the names of all the affected video files:
<15763078> <dynamiclink::FileServer> <0> OnSourceOpenFailed - filepath = /###REDACTED###/C0535.MP4 , error code = -10001 errorString = RPC connection terminated
<15763078> <dynamiclink::FileServer> <0> OnSourceOpenFailed - filepath = /###REDACTED###/C0528.MP4 , error code = -10001 errorString = RPC connection terminated
<15763078> <dynamiclink::FileServer> <0> OnSourceOpenFailed - filepath = /###REDACTED###/C0529.MP4 , error code = -10001 errorString = RPC connection terminated

And Console.app shows a new crash of the dynamiclinkmediaserver process—here is the top of one such crash report:

-------------------------------------
Translated Report (Full Report Below)
-------------------------------------

Process:               dynamiclinkmediaserver [58325]
Path:                  /Applications/Adobe Lightroom Classic/Adobe Lightroom Classic.app/Contents/Helpers/DynamicLinkMediaServer/dynamiclinkmediaserver.app/Contents/MacOS/dynamiclinkmediaserver
Identifier:            com.adobe.dynamiclinkmediaserver.application
Version:               24.0.0 (24.0.0.0)
Code Type:             ARM-64 (Native)
Parent Process:        launchd [1]
User ID:               501

Date/Time:             2026-03-27 14:38:11.8076 -0400
OS Version:            macOS 15.7.4 (24G517)
Report Version:        12
Anonymous UUID:        D9725948-341A-E3CF-BC58-A4D343C5DFB6

Sleep/Wake UUID:       ADB0D640-A448-4204-B2E2-DA2C98F7FC29

Time Awake Since Boot: 280000 seconds
Time Since Wake:       9392 seconds

System Integrity Protection: enabled

Crashed Thread:        37  Dispatch queue: com.apple.root.default-qos

Exception Type:        EXC_CRASH (SIGABRT)
Exception Codes:       0x0000000000000000, 0x0000000000000000

Termination Reason:    Namespace SIGNAL, Code 6 Abort trap: 6
Terminating Process:   dynamiclinkmediaserver [58325]

Application Specific Information:
stack buffer overflow

And here’s the trace of the crashed thread:

Thread 37 Crashed::  Dispatch queue: com.apple.root.default-qos
0   libsystem_kernel.dylib        	       0x186bea388 __pthread_kill + 8
1   libsystem_pthread.dylib       	       0x186c23848 pthread_kill + 296
2   libsystem_c.dylib             	       0x186b2ca74 __abort + 132
3   libsystem_c.dylib             	       0x186b1d818 __stack_chk_fail + 96
4   mc_mfimport                   	       0x11279d10c 0x11273c000 + 397580

I’ve reproduced this problem many times, and the crash is always a “stack buffer overflow” in a thread running “mc_mfimport”.

 

FYI: I migrated my LrC catalog a few months ago from an Intel-based iMac 5K 27” (2019) to this M4 Max MacBook Pro 14”.  The existing videos like these already in my catalog were imported successfully on the iMac, and I haven’t been able to import any of them successfully on this MacBook.  Just to be sure this problem isn’t stemming from the catalog migration, I also tried importing one of these videos into a separate, newly-created test catalog on the MacBook and got the same failure/crash.  Note that I didn’t use Migration Assistant to move any other Adobe-related files (caches, etc.) from the iMac to this MacBook, so I think it started with a clean slate (i.e. not polluted with any Adobe files created for an Intel-based Mac, for what that’s worth).

 

      1 reply

      PeterCJ
      PeterCJAuthor
      Participant
      March 27, 2026

      Important update: On further investigation, I’ve discovered that it is just one of these .MP4 video files from my Sony a7RV that is triggering the dynamiclinkmediaserver crash.  When I attempt to import all of them, the end result is that all of them fail to import, because the crash while building previews on the Import panel prevents any of them from being imported thereafter, and this problem has kept happening as I’ve accumulated more videos on the camera’s video card over the past couple of months (I use separate cards for videos vs. photos).  But if I copy subsets of these video files to a local folder and trying importing from there, I’ve found that I can preview and import all but one of them, as long as that one offending video is not in the import folder.

      So, this problem seems much narrower than it had previously appeared to me.  Regarding the offending video clip, it’s not especially large (~1m), but playing it with QuickTime, it does seem to have some unexpected audio static in the last few seconds—so I could understand that it’s corrupted in a way that prevents LrC from being able to process it.

      With this finding, I would be happy if LrC could identify that one or certain videos in the import view cannot be processed, report the offending video(s), but still proceed and successfully import the others, rather than mysteriously fail the whole operation with the vague error shown above.

      Claire H.
      Community Manager
      Claire H.Community Manager
      Community Manager
      March 27, 2026

      Hi ​@PeterCJ Wow,  thank you for the wonderful bug report and the recommendation. Since you have already identified that excluding the problematic video allows the import of the remaining files, keep that video file aside for further investigation. If you can share that file with us, we can test it and work to make our apps better! ^CH

      PeterCJ
      PeterCJAuthor
      Participant
      March 28, 2026

      Thanks, ​@Claire H.  I will keep the problematic video file aside, and I could share it with an Adobe engineer for investigation.  For what it’s worth, if I play this video file with ffmpeg’s ffplay command, when it hits the audio static, it starts spewing errors like these to the console:

      [hevc @ 0x129078cb0] Invalid NAL unit size (-1684550416 > 70674).
      [hevc @ 0x129078cb0] Error splitting the input into NAL units.
      [hevc @ 0x12907fc10] Invalid NAL unit size (-2057896536 > 370219).
      [hevc @ 0x12907fc10] Error splitting the input into NAL units.
      [hevc @ 0x129086b70] Invalid NAL unit size (1087079332 > 166540).
      [hevc @ 0x129086b70] Error splitting the input into NAL units.

      And then eventually:

      [mov,mp4,m4a,3gp,3g2,mj2 @ 0x12861c130] Packet corrupt (stream = 0, dts = 1394393).
      [hevc @ 0x12903a250] Invalid NAL unit size (299976891 > 106051).
      [hevc @ 0x12903a250] Error splitting the input into NAL units.
      [mov,mp4,m4a,3gp,3g2,mj2 @ 0x12861c130] stream 1, offset 0x184f14eb: partial file
      [mov,mp4,m4a,3gp,3g2,mj2 @ 0x12861c130] stream 1, offset 0x184f24eb: partial file
      [mov,mp4,m4a,3gp,3g2,mj2 @ 0x12861c130] stream 1, offset 0x184f34eb: partial file
      [mov,mp4,m4a,3gp,3g2,mj2 @ 0x12861c130] stream 1, offset 0x184f44eb: partial file
      [mov,mp4,m4a,3gp,3g2,mj2 @ 0x12861c130] stream 1, offset 0x184f54eb: partial file
      [mov,mp4,m4a,3gp,3g2,mj2 @ 0x12861c130] stream 1, offset 0x184f64eb: partial file

      Seems likely that whatever in this video file is triggering one or more of those errors is also the cause of the dynamiclinkmediaserver crash.

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