The strict form of the plan structure check serves as a validation tool for ensuring that top-down distribution has been carried out wherever necessary. The check is successful only if it only finds values at the end nodes ("leaves") of all the possible combinations of characteristics in the plan structure.
The error log lists invalid profitability segments and shows the path through the hierarchy down to the first incorrect characteristic. You can also display the path for each object directly in the plan structure.
It is not possible to lock the plan version as soon as the check runs without finding any errors.