Symptoms
After you upgrade your Microsoft Visual Basic 6 application to Visual Basic .NET or Visual Basic 2005, you may receive the following “exception” error message:
An unhandled exception of the type ‘System.IO.IOException’ occurred in microsoft.visualbasic.dll.
Resolution
This behavior occurs when all of the following conditions are true: The Visual Basic Upgrade Wizard upgrades Visual Basic 6 code that uses the Open statement to open a given file.
-and-You do not explicitly specify shared access to open this file.
-and-You attempt to open this file a second time without first closing it.NOTE: You may also receive this error message if you try to open a given file a second time (without closing the first file handle) by using the FileOpen function in Visual Basic .NET or in Visual Basic 2005 without specifying the Share argument.