TL;DR: There was a bug in Default Folder X 5.5 that resulted in it failing to launch correctly. Version 5.5.1 delivers a fix. If you’ve been affected and are having trouble updating to version 5.5.1, read on.
What Happened: First, my apologies. Default Folder X 5.5 introduced a new feature that tracks changes to files and folders synced via the cloud. Part of the startup process is to look at your current cloud settings to determine which folders need to be watched. In the case of Google Drive File Stream, Default Folder X didn’t properly read old settings files, resulting in the launch process being disrupted and leaving it running, but with no user interface (no icon in the menu bar, no toolbar in Open and Save dialogs, etc). This also breaks the auto-update mechanism, so you have to update to version 5.5.1 manually.
So yeah, big oops. In retrospect, I should have coded that even more defensively than I did so that the error would have been caught. I’m sorry.
How to Fix It: If you’ve been bitten by this bug, you have to manually download and install Default Folder X 5.5.1. Ostensibly, that’s not hard – just download
5.5.1 5.5.2 from this link:
Once the download completes, double-click on the .dmg file and drag the Default Folder X app to your Applications folder.
Now here’s the rub: If you ran the old, broken version 5.5, you may get an error message saying that you can’t replace it.
It’s still invisibly running, but there’s no clear way to quit it. The regular macOS “Force Quit” procedure – accessed by pressing Command-Option-Esc on your keyboard – won’t show Default Folder X even though it’s running. Here’s what to do instead:
1. Run Activity Monitor. It’s located in /Applications/Utilities.
2. Use the search field in Activity Monitor’s toolbar to locate Default Folder X in the process list.
3. Click on the (x) icon in Activity Monitor’s toolbar.
4. Choose Force Quit when prompted.
Now you’ll be able to drag the new copy of Default Folder X 5.5.1 to your Applications folder. Once it’s there, just open your Applications folder and double-click Default Folder X to launch it.
Again, my apologies for the hassle!