Why are the parameters in a ModelBuilder generated tool disabled?

Question

I created an interactive tool for generating Euclidean Distance Rasters and Reclassifying them afterwards. For the main input features I checked the:

"A list o values radio button" inside the "This value contains:" fieldset, from the Input Layers' properties.

When running the model from ArcToolBox I am able to insert the layers normally but only to change the parameters for the first layer. What is causing this problem?

The next image shows how the parameter fields are grayed out:

Answer 1

The problem was that the same property must have been assigned to all the parameters. This means that for all of them (using the ones on this example),

Right click on Output Cell Size - check "A list of values" radio button", Right click on Reclass Field - check "A list of values" radio button", and so on.

This will enable those fields for each of your input layers.