https://www106.zippyshare.com/v/OAHw01qb/file.html
Here is the video.
Did you update to the latest version? I know that support for 10 bit rec2020 HEVC imports was added, so worth a shot.
Your fileshare choice is questionable, It opens windows and flashes hijack alerts. Please use something mainstream like Drive or Dropbox.
That said, I "was" able to glean MediaInfo from your mp4.part file:
Video
ID :1
Format :AVC
Format/Info :Advanced Video Codec
Format profile :High 10@L5.1
High10p AVC Profile is neither popular nor universally deliverable {VLC will play it}, nor can it be opened in Vegas. It is leftover gravy that was quickly replaced by REC 2020 h265/HEVC. And that is what you should be producing for today's delivery. Assuming you have an HDR teevee.
That said, Handbrake may open your existing AVC High10p files and tranbscode them to something usable in Vegas. Going forward, to preserve 10 bits integrity, produce x265/HEVC at appropriate source levels, and ingest those into Vegas.
Here's an afterthought: Have you tried the Import Assist utility in Happy Otter Scripts? I leverages ffmpeg, so confidence is high.