In the process of trying out loading the files to the racing team, I got the 'unexpected error' popup a couple times. I think it occurs when loading results, when you click Choose File (and choose a file), click Import, and if the file has any problem and you edit the file and fix it, if you just click Choose File again and click Import again, you get the 'unexpected error' popup. This seems to be true even if you successfully fixed the file. It seems you need to abandon the Import, say by going to another page, and then find the race again and start the import process again. I think it's repeatable. It's a nit, but I wanted to mention it in case I forget.
From Mike:
In the process of trying out loading the files to the racing team, I got the 'unexpected error' popup a couple times. I think it occurs when loading results, when you click Choose File (and choose a file), click Import, and if the file has any problem and you edit the file and fix it, if you just click Choose File again and click Import again, you get the 'unexpected error' popup. This seems to be true even if you successfully fixed the file. It seems you need to abandon the Import, say by going to another page, and then find the race again and start the import process again. I think it's repeatable. It's a nit, but I wanted to mention it in case I forget.