I am using the fitting room in P13, following the instructions  in the manual. First I load lafemme into the  pose room and then I add a pair of pants. AllOkay

Then I go to the fitting room and allthough the fitting room  menu comes up the panel that asks if this is a new  simulation  does not show. Is there a reason /work around for this?

Stumped again.

The Fitting Room takes some getting used to. Nothing will show up in the fitting room when you first go to it because of how it duplicates objects being worked on.

If things auto populated, it would duplicate everything thing in the scene if you accidentally went to the fitting room.

Once you have the thing you want to convert and the figure loaded into a fresh scene, click on new to open the Session Name window.

In the top Object pull down, select pants you have loaded. In the lower Goal pull down, select LaFemme.

Click ok, and then they will appear in the Fitting room.

If for some reason the window does not appear when you click new, the UI may need reset.

Before you do that, make a UI dot to get back to where you have it now in case that is not the issue.

Does the pants belong to La Femme or do they belong to a different model?  If they belong to LF then it would not be necessary to use the Fitting Room unless you converting them to either a dynamic or conforming piece of clothing.  Another reason is that the original clothing needs further adjusting for a better fit.