Mates like hinge, wont work when i insert an assembly in to another assembly.
example - suppose I insert assembly 'A' which having hinge mate for door in to assembly 'B'
that hinge mate wont work in assembly' B'.
Make your part Flexible instead of rigid in the properties.
In the assembly, go to the tree and click on the sub-assembly that should be able to move (but doesn't). Then click on the "component properties" icon to open the properties for that sub-assembly. Where it say's "Solve as" (lower right corner area)...change it from Ridged to Flexible and then click on "OK".
Unless you're using SW2013 or earlier there's an easier way. See the first part of #1 at Frequently Asked Forum Questions.
Retrieving data ...