Sorry, I can't reproduce this scenario, I've tested it by downloading v56.0.2 from: https://ftp.mozilla.org/pub/firefox/releases/56.0.2/linux-x86_64/en-GB/

ShortenMe was also not updated so the only element in the chain that could have broke is Google API which shows 8 errors from last 2 days. I have no idea if these errors were from you and can only ask you to try again with a generic website, such as reddit.com

note: "Firefox Addons" website and some others are designed to not work (by firefox not me), the error message of the last update to shorten me should be clear enough for you to understand if this is the situation.

I really hope you can solve this problem.