I was running V13 and it quit on me - followed by an unusual message stating that there was an update available... The only thing I found was an update to V17...not quite the update I was expecting. Is there an update (NOT UPGRADE) to V13?
The last Sony Vegas Pro 13 build was #453. The last MAGIX rebranded release was #545. If you have build 453 you don't need to update to the MAGIX build. If you have a build that's earlier than #453, go to the Magix Download Center, enter your serial number for the product and and you should be able to get the last MAGIX build. (Help > About..., General shows your build and serial numbers.) You can also download as advised here, section 3.