Error code 100013 could happen for a number of reasons, but it is a Mac specific error. Generally it means you need to update either the device or the browser. Sometimes just doing a device restart will fix the issue, as well.
If this does not resolve the issue, here is a great troubleshooting guide that will take you through some more in depth steps, since the issue will eventually spread to other sites: https://www.fixmacissue.com/fix-error-code-100013-on-mac.html