Hello Jeff,
The problem might be because the file size is huge, like a whopping 582 gigs. VEGAS will also need huge space to run and preview that footage inside the software. Your computer’s C drive, where it stores stuff, only has 237 gigs of free space left. So, the lack of space on the C drive could be the reason it can’t open the file.
In my opinion, compressing the footage with any compression tools or cutting the entire footage into smaller videos and then opening them in Vegas one by one would be appropriate.
Hope this can help.