Hello!
When I tried to open the .ai file in Adobe Illustrator 10, it displayed an error which states, "Adobe Illustrator file format is having difficulties "
There may be a TMP file in the same folder, you can try renaming it to AI and see if this opens. Helped me on a couple of occasions but also has not worked in the past. If it useless, there is online service https://onlinefilerepair.com/en/illustrator-repair-online.html