I exported a Calibre Library from one Windows 10 system (From E:\ drive) and imported it into a different system (To C:\ drive, both same Calibre 4.2 [64 bit] version).
It seemed like import was going fine but at the end when opening the library, Calibre errored with "Failed to create calibre library at u'E:\\Calibre Library'.
I then reopened Calibre and pointed to C:\Calibre Library and it opened the library but I am not sure if the complete library was imported correctly.
Looking for ways to cross check new library against previous to confirm if all books and their formats and metadata have been successfully imported.
Hopefully if the library is fine, then, it means that the import errors unnecessary.
https://imgur.com/a/Fu4kmuv