A few things to try
Refresh and select the file again, try a smaller file or batch, and use a recent browser. If an in-app browser cannot save the result, open the page in Safari or Chrome.
Describe the issue
Copying adds browser, version and local error codes and locations from this tab, without filenames, file contents or URL parameters. Copying does not send feedback. On production domains, pressing Send email also writes your description (up to 2,000 characters) and these diagnostics to the usage log (see the privacy policy). When you write to us, include the diagnostic ID shown on this page and we can find the matching record directly.
Back to the tools. Try your own file.
Start compressing