Perform 'SHow LIBRary' to see what TSM thinks the situation is.
I would start at the OS level, using tapeutil's facilities to check
out accessibility and elements inventory of the library, to assure
that it can all be used at that level.  Whereas you apparently moved
to a new platform, whatever that is, verify that the device driver
through which you access the library and drives is modern and
functional.  Beyond that you may need to start over redefining
library, paths, and drives, depending upon what you find.  Look for
OS logging of any errors which may point out problems.

    Richard Sims