reason for flow.xml file corruption

Could some one explain me what would be the reason for flow.xml file corruption. ? I have done some changes in a flow service and deployed it to our test system as a patch. But I was unable to view/open that service in my test system due to the package was partially loaded n the load error was: "com.wm.lang.flow.WattEvaluationException: com.wm.lang.xml.WMDocumentException: [ISC.0042.9325] Element is missing end tag " .

Some one told me that itz due to flow.xml file corruption. I wanted to know how it was corrupted… during patch creation or during deployment? .

Kindly help on this.