Two sets of log excerpts demonstrate how macOS can prevent a user from opening a document, then mislead them into thinking it’s the app at fault.
Dock
Sometimes macOS decides you want to open documents using the wrong version of the right app. Here’s how to fix that.
My iPad docking port has been damaged. Does it now need an expensive repair?
How to make your Dock transparent, or otherwise customise it.
When I start my Mac up, the Dock crashes a few times. How can I fix this?
Up to OS X Tiger, we could group collections of shortcuts to folders under a single item in the Dock. This went, then returned. Here is how to use it.
The Eclectic Light Company 