ADE 4.5 Not Responding

I'm seeing ADE hang on "downloading content" aka "fulfilling content".   The bar fills up, then I get the Windows 10 spinning circle, and the app hangs for hours.  The book shows up in File Explorer, but cannot be opened without hanging again.  This occurs with NYPL books about 90% of the time, 10% of the time the book comes down cleanly.

I can kill the app when Windows says "This app is not responding" but this doesn't really help: I can't read the books I've checked out.

Anyone else seen this?  Any suggestions?

Michael