On my MAC (10.12.5) no problem in the past opening loaded drumkits for edit. I can dbl click on the kit name (for instance italicized NP Bosendorfer Jazz Trio XRp listed as ‘Local to Project’) in my list and click ‘yes’ to the prompt but the work space screen remains blank. I can however open those with a blue check box (listed as ‘User Library Drumset’). Did a link get lost and needs resetting when I managed files perhaps? The pop-up ‘Uncheck to remove from project’ doesn’t make sense here since there is no check box with these.
I have since gone back to the folder where the projects reside and suspect syncing to iCloud being on has played havoc here. Since I don’t access/use some files they may have gone to the cloud. I’m downloading and seeing some come back as accessible but a lengthy process and some quirky BBM behavior too maybe as it’s accessing files that are now available in the folder?