Google announced that they are shutting down, closing, their URL shortener service on March 30, 2019. Google first launched it in December 2009, and less than ten years later Google is going to shut it down.
Google wrote:
Starting March 30, 2018, we will be turning down support for goo.gl URL shortener. From April 13, 2018 only existing users will be able to create short links on the goo.gl console. You will be able to view your analytics data and download your short link information in csv format for up to one year, until March 30, 2019, when we will discontinue goo.gl. Previously created links will continue to redirect to their intended destination. Please see this blog post for more details.
Here is what https://goo.gl/ looks like now:
So if you are using them extensively, you should probably switch to bit.ly or some other service.
Forum discussion at WebmasterWorld.
Note: I am currently offline for Passover, this post was prewritten and scheduled to go live today.