When accessing an app using the SharePoint new look and feel, the following error is encountered on appredirect.aspx:
Sorry, something went wrong The query string “redirect_uri” is missing or invalid
The error occurs when accessing the new Sharepoint UI.
If you revert to the Classic SharePoint UI the issue is resolved. This is an issue with SharePoint itself, not a K2 issue.
MS premier ticket for Ref Support request number: 117040715571451