If you install the EPiServer.CMS.UI.* 11.19.1 packages the link in content are 'create new block' stops to work.
Instead of listing all possible blocks or blocks limited by the AllowedTypesAttribute you see nothing - the UI breaks and basically has nothing.
Quick workaround is to create thenew block in the Blocks tab in assets panel.
So stick with EPiServer.CMS.UI.* 11.19.0 packages. A support ticket about this has been created.