When you run the VIs in the development environment all VIs see the other VIs that are running and they can all use the same que if they get the que reference.
If a VI is built into an executable however, all it can "see" is the other VIs, ques etc. in the same executable...
The solution to your problem is thus either to build both VIs into one and the same executable or to build an interface to the que of the consumer application that allows the producer to send data into the que of the consumer, e.g. using a tcp/ip connection.