After running through implementation in PlanAhead, an error occurs during BitGen.
Can I run BitGen again without rerunning all of implementation?
There is no way to run BitGen again within PlanAhead 12.x. You can run it in the command line by navigating to the directory <project_name>\project_name>.runs\impl\floorplans\floorplan_x\impl_x.
This issue is fixed in PlanAhead 13.1.