I know how it should work, I have been lending books for a couple of year without to many hickups (there was the overdrive hiccup last Christmas season for a couple of months). And currently lending books from my local library in US (I think that worked last Christmas as well).
But I think the Swedish Library have updated to a later version of overdrive or whatever.
I guess I have to wait for the issue start hitting American libraries as well.
Lots of people having trouble in the US too.
Did you download the new version of Adobe Digital Editions 4.xx? (I did and had the same problem)
This is what worked for me:
First delete any reference to your book from your device. (GlowLight or Nook Color)
Remove your book from the Library in Adobe Digital Editions. DO NOT RETURN IT !
On Your computer you have a folder in Documents, MY DIGITAL EDITIONS. Open it and you will see your previously downloaded title. Delete it. ( This is just to eliminate confusion later)
Remove ADE from your computer.
Now download an older version of ADE.
Go back to your Library e book account and download the book again, according to the instructions:
How to transfer e book to a GlowLight.
If you have an older Nook ( Nook Color) it is not quite as complicated. Things should work as before. When you download your title, if you choose Open- your title automatically opens in ADE. If you choose SAVE, your book will go to your Download file. ( Unless you specify somewhere else. ) You will be prompted to go to the folder and open, click on the title and choose to open it with ADE. Then transfer it to your nook as in the past.
After you open your book in ADE, your title is stored in the folder MYDIGITAL EDITIONS in your Documents library. You may side load the book from your Computer to your Nook.