All buttons on the MRP workbench are disabled

All buttons on the MRP workbench are disabled.
I created a new MRP and lunched it..After all the programs are complete I went to workbench and could see the buttons.
I made certain modifications to the sourec MDS and re-lucnhed it..but now all the buttons are diabled..

what could be the reason

before any of the buttons on the planner workbench form (MRPSCPWB) become enabled the form needs to be populated with a MRP/MPS plan name (if one did not default in click on the flashlight icon). If the plan name is populated and the buttons are still not enabled, then make sure that the completion dates portion of the form is populated (the fields for Snapshot and Planner) If thses fields are not populated then the MRP/MPS plan needs to be launched.
To launch the plan, navigate to MRP (or MPS if MPS plan)/launch. select the plan name and submit the request.

The buttons on the Planner Workbench (MRPSCPWB) are NOT enabled unless the plan is valid (launched and completed normal) Note if a Plan has been run and complete normal and the workday calendar has since been rebuilt the plan will have to re rerun

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