There you can change the app used to open that document, and then click on the Change All… button to apply that to all other documents of that type. Then one day, you try opening a text document directly – for which Launch Services determines the app to use – and the wrong app starts up.Īs an isolated occurrence, the solution is simple: select that document in the Finder, and open its Get Info dialog (in the File menu, or Command-I shortcut). You might have changed that, so that they will open in your favourite text editor. text, and their variations, are set to be opened by TextEdit. By default, text documents with the extensions. The most common problem which occurs with Launch Services is that they misassociate a document type with an app. macOS now hides the database, and the only way of modifying it is through the undocumented command tool lsregister, which is not even stored in one of the usual locations for command tools. In early versions of Mac OS X, the database was kept in two files, ~/Library/Preferences/LSApplications and LSClaimedTypes, but those days are also long since gone.

Way back in classic MacOS, the Finder’s desktop databases maintained that information, and it was not uncommon to have to rebuild them periodically to resynchronise document and app icons. Requires a database which tracks apps and their capabilities, and document and URL types and how they should be represented.

providing ancillary information about files and URLs, such as an associated icon,.

maintaining lists of document and URL types which an app can open,.

identifying the default app with which to open a document or URL,.opening documents or URLs in other apps,.In yesterday’s article, I listed the main tasks of Launch Services, and explored how it appears to perform just one of them.

Onyx for high sierra