Rack 2.5 Mac, Linux, Windows, crashes, crashes crashes

the salty to be downtalked user again:

Asking me how fast this post is deleted this time?

Does someone got v2.5 working on a Mac?

Here it crashes with every existing file I tried….

Every time the same: ‘’’ [27.862 fatal adapters/standalone.cpp:49 fatalSignalHandler] Fatal signal 6. Stack trace:

23: Rack(fatalSignalHandler(int)+27)

22: libsystem_platform.dylib(_sigtramp+29)

21: ???(0x0+0)

20: libsystem_c.dylib(abort+123)

19: libsystem_c.dylib(err+0)

18: libRack.dylib(rack::engine::Engine::updateParamHandle_NoLock(rack::engine::ParamHandle*, long long, int, bool) (.cold.1)+35) ‘’’ Going back to 2.41, by a lot of manual work, the existing file are working again!


That sounds like something you’ll need to contact VCV support for (support@vcvrack.com. I’m not sure anyone here will be able to help you based on what you’ve described.

This should be a warning to the Mac people not to install the new version. And writing to support was not very helpful in the past for Mac problems.

It seems Solution is auto generated ?

intel or ARM mac!?

It seems there is a bug in Rack’s engine with ParamHandles (used by MIDI-MAP and many of my modules) in the pre-release of 2.5.0. I reported it to VCV’s support a moment ago:

  1. Start with the default template patch
  2. Add MIDI-MAP module
  3. Map any parameter in the patch, it doesn’t matter which one, a MIDI assignment is not needed
  4. Close Rack
  5. Start Rack, the previous patch is autoloaded
  6. Remove MIDI-MAP module

On the last step Rack crashes.


Yep - I reported the same thing to support last night. It affects Windows as well, though it crashes on patch load for me.

Some other modules that also crash my 2.5 on Windows upon patch load include (not complete):

  • Stoermelder uMap, CV-Map, (I suspect Transit, but not tested)
  • MindMeld PatchMaster

Linux too.

Rack: src/engine/Engine.cpp:1139: void rack::engine::Engine::removeParamHandle_NoLock(rack::engine::ParamHandle*): Assertion `it != internal->paramHandles.end()’ failed. Aborted (core dumped)

Additionally the 2.5.0 install has moved stuff around so I can’t revert to 2.4.1 without undoing that, grrr.


the salty to be downtalked user again:

You all can think what you want, but in my eyes it is very important not only to inform support, but also inform all users via the forum to avoid all this rollback hassle!

For me also the question is why moving working stuff suddenly around?


Are you sure? You can have multiple rack user locations on the same computer and switch between them when launching via command line. I should think reverting to 2.4.1 would automatically revert to using the old user location by default.

2.5.0 moves resources out of 2.4.1 folders. Not copy, actually move!

It moved the user folder when really it should’ve copied so as not to break old versions.

From changelog:

  • Move Rack user folder to:
    • Mac: ~/Library/Application Support/Rack2
    • Windows: AppData/Local/Rack2
    • Linux: ~/.local/share/Rack2

Really? Am I misremembering? I thought Rack Free and Pro shared many of the same resources, and I upgraded only free to 2.5, and my pro 2.4.1 pro is still working fine.

As far as I can tell 2.5 on Windows simply created new folder structures in …/AppData/Local/Rack2 and left my data in …/Documents/Rack2 alone.

Or are there other resources I am not aware of?

Not my rig, it picked up the user folder “Rack2” and moved it. When I put it back and reopened VCV, it did it again. Old patches with Recorder active are buggy, because the old location for the recordings is gone and Recorder complains about it and will not easily be directed to new folder.

Windows 10 user

1 Like

2.5.0 moved my user folder to ~/Library/Application Support/Rack2 so 2.4.1 would need to have it moved back to function…

Thanks. Maybe my dying hard drive saved the day! It is seemingly randomly corrupting some files.

I didn’t pay much attention, but I did run into a hiccup during installation of 2.5. Maybe a corrupt file prevented the installer from moving my user folder. So now I have one in both the old and new locations.

I was concerned with the files relocation, so I decided to wait a bit before updating to the 2.5 pre-release. I’m on Windows.

1 Like

I wish I had.


the salty to be down talked user again:

The buggy VCV Rack 2.5.0 prerelease version is still available for download at:

Were are the guys that were deleting my posts within minutes in the past?

This version should been taken down at once to avoid more and more hassle for the people, its online since 17 hours!

1 Like

Please changes “Rack 2.5 Mac crashes, crashes crashes” in

"Rack 2.5 Mac, Linux, Windows, crashes, crashes crashes!

1 Like


1 Like