it’s almost certainly a permissions (or ownership) problem, but it’s specifically about the macOS temp directory Roon is trying to use for its lock file, not about Roon’s own app bundle.
Here’s what I found out doing a bit of googling and AI queries. Info below was cross-checked using Perplexity as main source, with Clause and ChatGPT as reality checks. It also maps to what I think I know.
Roon on macOS creates a “required lock file” in the system temp directory when it starts.
If your user can’t write to that temp directory, you get the “Fatal error – could not create required lock file” message.
Under current macOS releases:
-
/tmp is a symlink to /private/tmp.
-
/private/tmp should be owned by root:wheel and world‑writable, typically with sticky bit: mode 1777.
-
If those permissions are broken (e.g., not writable for “everyone”), apps like Roon that expect to write lock files there will fail.
So it’s a permissions/ownership problem on the temp directory, not on Roon itself.
If you’re not comfortable using Terminal, you may be able to fix this another way:
Reboot into macOS Recovery and run Disk Utility → First Aid on the system volume, which can catch some filesystem/permission problems at a lower level.
- Check free space in menu → About This Mac → Storage, and free up space if the system volume is nearly full; lock‑file failures can be a symptom of “no space left on device.”
–Terminal Stuff Follows–
Quick diagnostic on the iMac:
On the 2017 iMac, in Terminal, run:
bash
ls -ld /tmp /private/tmp
You should see something like:
bash
drwxrwxrwt … root wheel /private/tmp
lrwxr-xr-x … root wheel /tmp → private/tmp
Key points:
-
Owner should be root, group wheel.
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Permissions should be drwxrwxrwt (the t is the sticky bit, and the effective mode is 1777).
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If /private/tmp isn’t writable by everyone, or the sticky bit is missing, that’s your problem.
Fixing the permissions safely
If /private/tmp is wrong, the canonical fix is to restore the correct mode and ownership, not to “chown it to your user” (which works short‑term but breaks the system convention).
In Terminal:
bash
sudo chown root:wheel /private/tmp
sudo chmod 1777 /private/tmp
Then reboot the Mac and try starting Roon Server again.
If permissions look correct but Roon still fails
If ls -ld shows the expected root:wheel and drwxrwxrwt on /private/tmp, but Roon still complains:
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Make sure there’s actually disk space available on the system volume; “cannot create lock file” can also appear when there’s no space left.
-
Fully remove and reinstall Roon on that Mac, then when macOS asks for permissions (Documents, Music, etc.), grant them.
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Confirm you’re not running Roon under some restricted user or sandboxed context that denies write access to /private/tmp.
Note: I don’t think any 3rd-party utilities can solve this problem.
