Can't replace the Evaluation.bpmn by using it's original file.

I did some changes in Evaluation.bpmn, after that coming error in Evaluation.bpmn. I tried to fix that I couldn't, After I try to replace the Evaluation.bpmn. But first time it's doesn't allow to do that. But when I did again after closing everything it can be replace by original file. After I restart the process and check eclipse, there is the error as there in previously.