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johnrellis
Genius
October 7, 2025
Question

SDK: LrTasks.execute() crashes LR 14.5.1 on Mac OS 26.0 / Apple Silicon

  • October 7, 2025
  • 2 replies
  • 107 views

[Adobe doesn't accept bug reports of LR 14 on Mac OS 26, so I'm posting this here to inform other plugin developers and users and perhaps Adobe developers, if they're interested.]

 

Plugins sometimes crash LR 14.5.1 with Mac OS 26.0 on Apple Silicon Macs when they try to run a child program using LrTasks.execute(), with the error in the crash log, "crashed on child side of fork pre-exec".  If this bug continues with LR 15 (officially supported on Mac OS 26), it could have a serious impact on many plugins.

 

A similar bug occurred a year ago starting with LR 13.5, on just Intel Macs, and wasn't fixed until 14.5. Adobe's fix was suboptimal, serializing all invocations of LrTasks.execute(), creating a real performance hit for plugins that invoked multiple instances of programs in parallel (e.g. Exiftool). A better fix would have been to serialize the lower-level invocations of the operating system's fork/exec system calls, which would still allow multiple instances of LrTasks.execute() to proceed concurrently.

 

I've experienced one crash with a plugin running the command-line utility "osascript", and a user of my Any Source plugin experiences continued crashes when "sqlite3" is run.

 

My crash report is attached.

 

Note that Adobe's crash reporter doesn't get invoked with these crashes, since they occur in the child process of LR after it forks but before it invokes exec to replace itself with the child program.  The Adobe crash reporter just monitors the main LR process, not the child process.

 

 

2 replies

johnrellis
Genius
February 5, 2026

I’m getting these crashes from LrTasks.execute() perhaps every week or two on average. The most recent one was LR 15.1.1 / Mac OS 26.2.2.  Crash report attached.

johnrellis
Genius
October 7, 2025

@Rikk Flohr: Photography, just an FYI in case the developers are interested in getting a head start on potential issues with plugins on Mac OS 26.