"Device Not Authorized for AdobeDRM" error on Kobo Sage.

The Kobo Sage is in fact authorized as is my PC, and worked for a couple weeks then stopped.

I've De/Re-authorized and scrubbed Sage and PC and Libraries repeatedly to no effect.

When UNPLUGGING the Sage all transferred files are then reported as "Importing" which is apparently code for being tightly locked with AdobeDRM again as they're readable on the PC.

My Sage is now a highly-priced paperweight.

Any ideas out their? I'm pulling my hair out over this for 2-3 weeks now.

Thx in advance for your time and attention - M