I get an error message that says my ipod classic is not linked to my itunes library but I am not linked to any other itunes library.

iPod Classic. MacBook Pro. OS X El Capitan, version 10.11.6. iTunes 12.4.3.1

I tried to transfer (manual manage) some new purchased TV shows from iTunes to my ipod and I received an error message:

My ipod is only linked to this library and no other. When I try to transfer my music and some older TV shows from iTunes, I do not get the message. I thought it might be associated with the last iTunes update but the date of my last transfer (that was successful) was after the latest iTunes update.

Does anyone know how to link my ipod back to iTunes without removing my videos and transferring them back again?

Thanks!