RE: Scan Manager Desktop not working?  Ignore everything posted, it's not your scanner. Here is the solution:

Short answer: download and install the updated paperport scanner connection tool. https://knowledge.kofax.com/MFD_Productivity/PaperPort/Troubleshooting/PaperPort_Scan_button_is_gray... .  This works for Windows10 despite the win8 reference.

Long answer: too long. it goes back to Win8. Nuance is now Kofax. short answer again: Quickbooks doesn't really care and relies on the community to fix their s***.  Sad..