I can't load a DVD- into my "Import Media File" program

I have a Sony Camcorder that is +R DL Compatible. The software that came with the purchase of this camera won’t import a DVD- disc that a friend loaned me to put into my system to open in my Vegas Movie Studio. I load the DVD- in my CD Drive and click on “Import Media File” and it says that it is unable to read the disc because “disc was not created by a Handycam or by this program”. So I copy the disc into one of my Folders as DVDCAM.IFO and using my Vegas Movie Studio I try to bring it in and it says “Warning: The file is an unsupported format”. Is there a software program that could import ANY DVD into my computer (Toshiba Laptop "Satellite A215-S4757) and make it a supported format? If not, at least make a DVD- a supported format. This DVD has memorable moments I want from an awards ceremony.
Any help is greatly appreciated. Thank you.

DVD Decrypter should be able to handle it, provided that the disc was finalised in the original recording device.

Moved to Video Edit Software section.

Time to contact and ask the support from either “Vegas Movie Studio” or Sony.