When trying to access the "Manage Workflows" page from the "Workflow Settings" menu in the ribbon the following error might occur:

Access the page from a full library view page.

Cannot access the Workflow gallery from list view webparts.

The error indicates that the Workflow Designer and Manage Workflows pages are being accessed from a list view webpart, possibly directly from a teamsite homepage. Nintex Workflow components can only be accessed from a full library view page.

The Nintex .aspx pages, including the Workflow Designer, rely on a List Id being passed to the page by SharePoint. This is not available from a list view webpart.