Error: Undefined reported from webserver

This error was just reported near the end of a sizable export:

The following error was generated by your server:

undefined

function () { if ( list ) { // First, we save the current length var start = list.length; (function add( args ) { jQuery.each( args, function( _, arg ) { var type = jQuery.type( arg ); if ( type === “function” ) { if ( !options.unique || !self.has( arg ) ) { list.push( arg ); } } else if ( arg && arg.length && type !== “string” ) { // Inspect recursively add( arg ); } }); })( arguments ); // Do we need to add the callbacks to the // current firing batch? if ( firing ) { firingLength = list.length; // With memory, if we’re not firing then // we should call right away } else if ( memory ) { firingStart = start; fire( memory ); } } return this; }

I was trying to export two types of posts that had many entries. I’m now trying each separately, but the page told me to report this.

EDIT: The initial attempt to export the smaller post type immediately came back with this error, though another attempt after waiting a bit succeeded.

https://www.ads-software.com/plugins/wp-csv/