[Aristoexian]

I've read every reply concerning these errors in the forum yet nothing helps. Errors began after I renamed the USB drive (non-networked) that houses my formerly perfect Calibre library. I used the "Switch/Create Library" to re-locate my library and now about every fifth line I touch produces these errors.

These occur when I simply touch the line of the title. I've not been working with covers nor are any other apps open. (I have no virus or disk monitoring software and Activity Monitor shows nothing else that could interfere.) I'm sure it's related to my directory change. I ran the permissions command suggested and of course run Disk Utility on both external drive and Mac. Has anyone managed to tame these? If no other ideas should I try saving my library to another USB, though this one worked fine for years?

I'm sorry for this monstrous screenshot. I've reduced it in Photoshop but it blows up again when I paste the link here.

[Added as attachment]