Sharing excel file using vb.net

Hi!
I have an excel file and a form created in visual studio 2013. Using the form the data is inserted in excel file. Now, this file and form will be used by several users at the same time through a common drive. Now, the problem is when I share the file and they enter data in the form and click submit button which transfers the data from the form to excel, an error occurs:

"unhandled exception has occurred in your application. If you click continue, the application will ignore the error and attempt to continue. If you click quit, the application will close immediately. Exception from HRESULT: 0x800A03EC"

How do I correct this? Please help!

Someone Please Help!