System.ExecutionEngineException Occurs in Windows Phone 8.1 XAML

Question

H!! I am Developing windows phone 8.1 application. which has functionality to import videos and export videos into my app. But after when I perform one or two operation in my app like importing or exporting videos it gives me error like System.ExecutionEngineException occurred in Unknown Module. I am importing and exporting videos from knownfolders to my localfolder and code for that is not wrong. I am able to import or export videos one or two time but after error occurs. please give me right solution. Thanks in advance.