Object checkpoint fails

Hi,

  I have created one object checkpoint by storing all the child objects related properties of one popup window like captions, input field lengths, labels related to buttons, control types of buttons, default values etc. and when I was executing the same, the checkpoint is getting failed with an error message

"Checkpoint "Objects.ProductMaterialPopupWindow" not found

 

Other object checkpoints were passed and only this popup related one is getting failed. 

If I am trying to delete this checkpoint from Stores --> Objects, I am getting the error and I have only one option i.e., to close the entire tool (Pls check the attachment for the error message)

Please suggest me a solution.