Missing mask variable warning

I am trying to modify parameters of simPowerSystems library, for example an AC4 block.

I realized that I had to disable the link from the library to put mu own variables in through the GUI (Mask), then I did the same with the internal sublocks.

The problem is that the MASK is not able to communicate with the other blocks inside the main model to update the parameters, and the a warning window appears saying:

 "Missing mask variable warning":

What I am doing wrong?