I have created several document libraries in different locations on an established SharePoint 2013 Site Collection in which I have added the document set content type. I cannot create a document set in any of them without errors. When I create a document set from the Files tab on the ribbon, I get the error, "Sorry, something went wrong / File Not Found." This happens in all document libraries when creating a document set.
The document set actually does get created. However, I also can't open the document sets; I get the same error.
SharePoint seems to be looking for /XXXX/Forms/Document%20Set/docsethomepage.aspx. I can see that file in SharePoint Designer, but if I try to preview it in the browser, the same error message appears.
Can anyone assist with this please?