System.IO.IOException : The process can not access the file **** because it is being used by another process.

Hi,

I have developed a Powerpoint Addin. when i want to add file in the presentation pptx file, I get an exception at :

Package package = Package.Open(packagePath, FileMode.Create) : System.IO.IOException : The process can not access the file **** because it is being used by another process.

Any one can help me how to solve this ?

Thank you so much.

Best regards.