12/24x6DAT library fail of hdw predicted

I have multiple 12/24 Dat Autoloader drives and keep receiving the library failure of Hardware predicted. I have tried almost everything. I have used new tapes, I have switched out the cartridge, I have relabled the media, I have cleaned the dat drive, I have replaced the dat drive. I don’t know what to try next everything was working fine for over 6 months then all the sudden the errors stated appearing. Any ideas? Anyone?