Symptoms
When you delete a folder in the web portal of SQL Server 2016 or 2017 Reporting Service (SSRS), the folder is deleted, but you may also receive an error message that resembles the following:
The folder "folder_name" does not exist. It could have been renamed, moved, or deleted.
Resolution
This fix is included in the following cumulative updates for SQL Server:
Cumulative Update 1 for SQL Server 2017
Cumulative Update 5 for SQL Server 2016 Service Pack 1
About SQL Server builds
Each new build for SQL Server contains all the hotfixes and security fixes that were in the previous build. We recommend that you install the latest cumulative updates for SQL Server:
Status
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
References
Learn about the terminology Microsoft uses to describe software updates.