This File Error is given by our Prepress team if you have uploaded Spot UV files that contain other colours than just 100K black (CMYK 0, 0, 0, 100).
The areas for Spot UV treatment will need to be defined in black ink, and areas for no UV treatment will be left white. The black colour used must be CMYK Black only - with no greys, gradients or other colours. This means your artwork meant to be printed should NOT be included in your file for the Spot UV layer.
File setup for Spot UV can be a complex process and should be completed by an experienced designer. If you would like the Jukebox Print Design team to create your Spot UV files, please submit a request under your Account Centre - Design Services tab. An additional cost will apply for this service.