Looking at the serial number details for that Dash, you do not have Display Creator enabled on that Dash so you will not be able to use the Display Creator functions with it.
Stephen Dean MoTeC Research Centre Melbourne, Australia
Contact your MoTeC dealer, give him your C125 serial number and order the Display Creator option. When you get back an enable code use Dash Manager->Online->Dash Options (Upgrades), and enter the enable code. Then try the steps you used above.
Any MoTeC dealer (in your country) can sell you the Display Creator upgrade. The Dash does not need to be removed, the upgrade is done via the enable code using Dash Manager.