"because someone else is using it"

I have a Mac which is shared between family members via the “switch user” feature of OSX. Multiple users may be logged in, but only one is active at a time. Obsidian will not open in one logged-in account if it is open in another. It displays a pop-up saying that it won’t start “because someone else is using it”.

In my understanding, each individual should be licensed to use Obsidian, and the way that the “switch user” feature of Mac works will guarantee that only one user is interacting with Obsidian at a time, if that even matters. Why is there code in Obsidian that specifically blocks it from being open in more than one account at at time on a Mac?

this is not in Obsidiian, this is Mac/electron thing.

The Atom editor is based on Electron and it does not behave in that way on Mac. At this moment I have Atom running under two logged-in accounts on that same machine.

Is Obsidian doing something with Electron that causes this?


As a test I tried another Electron application, Left (https://hundredrabbits.itch.io/left) which is open source. Like Atom it does not block multiple users from opening the app simultaneously. Clearly this is an Obsidian problem, not an Electron problem. Can we classify this post as a bug report?

To block simultaneous access by different users some shared resource must be locked. This would normally be either a file or a port. I’ve checked using lsof and thus far I can’t find the culprit. Is Obsidian making use of some port or some file that is not specific to the user?

Seems to be caused by the misleadingly named LSMultipleInstancesProhibited which sounds like it would make the app single instance, but actually prohibits it from running under multiple users.

Will fix with a new installer update once we make our next public release.

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Thank you for the quick attention and fix.

I just found Obsidian yesterday and it seems to be exactly what I was looking for in a notes app. I work for a non-profit public university, but if they don’t want to spring for the commercial licence anyway then I’ll at least buy a personal Catalyst license.

Thanks for your excellent work!