How does OSX tell what app to open when you double click a file?

Bob Sneidar bobsneidar at
Tue Aug 6 18:16:08 EDT 2019

Ouch! Seems like an installer that replaces the prior version with the current one is in order. 

Bob S

> On Aug 6, 2019, at 14:59 , Paul Dupuis via use-livecode <use-livecode at> wrote:
> Actually, this issue is that some of our users keep multiple versions of our App installed. In most cases, when the user double clicks a document from our app, the MOST RECENTLY INSTALLED version launches, but in some cases, and older version launches.
> In those instances where an older version launches, the user swears that they have never used "Open With" or done anything (that they are aware of) to set the default app for our document extension to an older version.
> So really, I am just trying to understand how OSX figure out how to determine what app to open for a document.
> For example, if you drag installed 5 apps, APP1, 2, 3, etc, that all had a info.plist defintion for a .xyz file extension onto a virgin OSX system out of the box and then double-clicked a .wyz file, which of the 5 would open?

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