You and XYZ were working on this at the same time. Somebody else finished before you did so your work was not saved.

I appreciate you for logging into another browser to save your work, Mj. I have information about the error you've experienced and direct you to the best help to fix it.

When you receive the message about simultaneous access, it usually means this error occurs when multiple users are working on the same transaction in QuickBooks Online. One user saves changes while another is still working on another version of the transaction.

If you're the only one using your QuickBooks, reaching out to our support team directly could be beneficial. They can provide insights tailored to your specific system issues and help you resolve them quickly.

Moreover, here's a guide on how to batch invoices accurately, you can refer to this article: Create and send multiple invoices in QuickBooks Online Advanced.

You can follow this article for future reference if you will create reports with your transactions: Create and edit reports in Spreadsheet Sync in QuickBooks Online Advanced or Accountant.

Keep me posted if you have further concerns with managing your account and other QuickBooks-related work. I'm always ready to give assistance and resources. Fill me in by leaving a comment below.