Http://dhtmlxgrid.appspot.com/export/excel not Working

The service http://dhtmlxgrid.appspot.com/export/excel is not working
help…

Failed to load resource: the server responded with a status of 500 (Internal Server Error)

Thank you for your report. We’re working on that problem.

When will it be restored?

Currently, it is working:
https://snippet.dhtmlx.com/5/798bc78e2