WorkCenter view showing invalid after having assembled

Hi, experts.

     I added a work center view to Cost and Revenue WorkCenter. It works fine before assembling the solution.But after having assesmbled, my custom work center is missing. In the Available Workcenters and Views tap of Application And User Management, my custom work center view under Cost and Revenue WorkCenter is showing "Invalid WorkCenter View". But the odd thing is both my custom workcenter and custom workcenter view are showing valid.

Regards

Fred.