DLP & Watermarking

Hi,

I am having a super hard time figuring out how the DLP Watermark tool within FortiExplorer can provide me with anything usefull :) 

I have 1000D in Flow mode, running on 6.0.4. I made my DLP Sensor (had to use cli to get the 'watermark' option)

Sensor:

Type: Files

Watermark: Sensitivity: Critical , Corporate Identifiser: Somethingsomething

I examine all services, and my action is block.

I then made a policy putting the DLP sensor I made in the rule, all the rules, everywhere.. :) I then started moving my watermarked file around and there is nothing..absolutley nothing happening. So - it is probably me that has missed out on something ? :) ...help ?