Did you try the solution suggested by David? Are you still facing the issue?
The error message (Execution of the workflow failed. Reason: CreateInstance failed for type 'System.IO.FileInfo'. No parameterless constructor defined for
this object.) suggests that the FileInfo class does not have any constructor which takes zero parameter. In fact the FileInfo class has
only one constructor defined which takes one string parameter, the path of the file.
FileInfo fi =
new FileInfo (@"C:\Program Files");
So you need to create the Activity with an input parameter which you must provide (i.e. RequiredInput).
You can also find a sample project for FileInfoInitializer