Trying to login into the SDL Trados GroupShare 2017 WebUI using Windows Authentication is not possible and the login screen is displaying again.
If the loading takes a bit longer than there is also the error message display:

An error has occurred


Example:

Solution: Install Cumulative Update 1 (or higher) 

To solve this issue install the Cumulative Update 1 (or higher) for SDL Trados GroupShare 2017 that is planned to be released at the end of February 2017.
More information can be found in the Release Information section of our Knowledge Base at SDL Gateway here:

• Release Information section for Translation Productivity products

The SDL Development team is aware of this problem and is working on a solution that will be addressed with a Cumulative Update for SDL Trados GroupShare 2017. Until a permanent solution is in place there is no workaround available.

Related article(s):

• Trying to open server-based Translation Memory displaying the error: 'Response status code does not indicate success: 401 (Unauthorized).'