Exporting Dual ISO, But Can't Rename to DNG

[luke1100]

I was exporting some dual ISO images and ticked the Windows prompt box saying (always trust this program).  Now I can't export, I see the errors can't rename file to imagename.DNG and AgImportSessionAddOnePhotoToLibrary.

So, any help on how to reset the Windows prompt, or other options would be grand.  I've been searching Google, but I haven't seen a clear answer. 

Thank you.