Does it only affect Chrome?
Chrome does some unusual things to block other DLLs from being loaded into its processes (which in turns makes Opus even less likely to be involved), as well as to isolate parts of its UI (like that dialog) from processes for the browser itself.
Opus has no real interaction with the File Open dialogs, other than changing the file type registry settings for folder double-clicks. (That would only affect what happens when you double-click a folder, not what happens when the dialog opens.)
Listary probably may interact with those dialogs (that is its purpose), and in turn talks to Opus. So it's possible Listary is hanging, maybe because of something which changed in Opus. (Can't think what, but it's possible.) I don't know how Listary works exactly but if it has both services and a UI process, it might make sense to uninstall it completely as a test of that. (Then install it again once done testing.)