Along the same lines as in part V (maybe a tad bit less annoying, but still quite up there) is the disappearing of exporting presets.
I use the export function out of Lightroom extensively and I made some custom user presets for exporting files, with or without post-processing actions in Photoshop.
And the same thing happens here as it does with the metadata presets.
As soon as you change catalogs the user presets are gone. “Luckily” the last used information is kept in the fields, so you can salvage at least one of your presets, but all the other ones you will have to redo.
The ones that are “hard wired” in the system will stay. The post-processing actions for example, they are still there. But those are actual physical files on the hard drive. Apparently these user customized export presets aren’t. They seem to be temporary files attached to the currently opened catalog.