Error when downloading borrowed book

[#1]

Hello,

My Adobe Digital Editions 4.5 was working last time I used it, but now it gives me an error when I try to download a borrowed e-book or return a borrowed item.

It says: "Unable to download. Error getting License. License Server Communication Problem:
E_LIC_LICENSE_SIGN_ERROR"

or

"Unable to return. Error returning item. License Server Communication Problem:

E_LIC_LICENSE_SIGN_ERROR"

I already tried to update the Adobe app and also my computer. I'm using MacBook Air and macOS Catalina 10.15.3. What should I do?

[#2]

Hello,

My Adobe Digital Editions 4.5 was working last time I used it, but now it gives me an error when I try to download a borrowed e-book or return a borrowed item.

It says: "Unable to download. Error getting License. License Server Communication Problem:
E_LIC_LICENSE_SIGN_ERROR"

or

"Unable to return. Error returning item. License Server Communication Problem:

E_LIC_LICENSE_SIGN_ERROR"

I already tried to update the Adobe app and also my computer. I'm using MacBook Air and macOS Catalina 10.15.3. What should I do?

[#3]

Problem solved! I found the answer here: https://community.adobe.com/t5/digital-editions/cannot-download-book-from-public-library-anymore/td-...