Hello,

500 errors are internal server errors and could be caused by several factors including config or bad code. Please check the server php error logs and let me know the error details so that I can suggest.

If you are not sure about server error logs, you can enable app logs by changing the log_threshold to 1 in the app/config/config.php folder and then try to import again to produce errors. Lastly check the latest error logs in the app/logs/ folder.

Thank you