It is easy to check in CATIA if you took all the degrees of freedom from an assembly by using the B.I.Essentials command like in the example below (follow the color legend, and you will immediately know what to do 😊 )

Using B.I Essentials to check the degree of freedoms

A little tip: put the Fix In Space command in the Action Pad first (of course, only if you want to use this quick method to take over all the degrees of freedom and reduce the number of constraints needed for this 😊).

This allows you to place the Fix In Space constraint without leaving the visualization provided by B.I.Essentials.

Adding command in Action Pad

After finishing this operation, when you will click on Free in B.I.Essential panel as shown in the image and nothing is selected in the tree, you can be sure that all components don’t have any degree of freedom.

Everything is constrained in the assembly