After many months of using 2sxc; building sites, importing content, without any problems, I'm encountering an issue when importing content to a new site. The only error message I see is "Had an error talking to the server (status 500)." If I use a Content export from a previous date, the import works fine. This happens in multiple portals on the same server, and on both my production and testing servers. Almost seems like a corrupt export file, but all repeated exports I've tried have the same problem.
F12-console doesn't reveal much, but I've attached the .log export. There is nothing in the Admin Events Viewer related to 2SXC, and nothing in the server event viewer either.
Developer Console log export: https://gotrwebsite.s3.amazonaws.com/pintiva.biz-1485972308931.log