Parent State ID: 21
State Depth: 5
Action Taken: unstack(block_a, block_b)
Action Reasoning: To achieve the goal state, block D must be placed on block C. Currently, block C is clear, and block D is not supporting any further blocks (it's at the bottom of the stack under A and B). The best next action is to unstack block D from block B, since block D was mistakenly part of the stack with blocks B and A, and move it to block C.
State Description: Block A is now held in the hand and is not clear. Block B is on block D and is clear. Block C is on the table and is clear. Block D is on the table and is not clear. The hand is holding block A.
Action Path: ['unstack(block_b, block_c)', 'stack(block_b, block_d)', 'pick-up(block_a)', 'stack(block_a, block_b)', 'unstack(block_a, block_b)']

INACTIVE REASON: deactivated because diagram generation failed or invalid action chosen: Action does not align with goal state requirements.
