If you try to update TextExpander and get an error message saying: “TextExpander can’t be updated when it’s running from a read-only volume…”, it’s likely because of a security measure in macOS called translocation.
Translocation can happen when you use an application other than macOS Finder—for example, Hazel, LaunchBar, or Path Finder—to move TextExpander into the Applications folder. It can also happen if you download TextExpander as a zipped file directly to the Applications folder and unzip it there.
To fix this, drag TextExpander out of the Applications folder and into your Desktop while simultaneously holding the Command key. Then, check your Applications folder. If TextExpander is no longer there, then you’ve successfully moved it out of the Applications folder. Drag it back in.
If you’re still having trouble, download a new copy of TextExpander and drag it into the Applications folder via macOS Finder.