Hi Robyn,
Thanks for the information. Now we know the issue is: can’t open the workbook created by Office 2011 for Mac in Office 365 Online.
As the issue is related to the Office 365 Online, we first suggest him change other Internet browsers with private or incognito window to see the result.
If the issue happens to multiple Internet browsers with private or incognito window, this issue may not be related to the Internet browsers. Then please check the information below:
Please confirm if the issue only happens to a specific workbook or all workbooks created by Office 2011 for Mac?
If the issue only happens to a specific workbook, we suggest he can try the steps below:
- Open the workbook in Excel 2011 for Mac.
- Create a new workbook from within Office Online
- Copy sheets to the new created workbook to see the result.
- If copying sheets can’t help, please try to copy content in cells directly to the new created workbook sheets Online to see the result.
If the issue happens to all the workbooks created by Office 2011 for Mac, please create a new workbook in Office 365 Online to check if the new workbook created directly by Office Online can work well.
If that is convenient, we appreciate you can get the example problematic workbook from your boss, upload it to us so we can test it by our side to see the result. To protect your privacy, I have sent you a private message to collect them. Please access it
via this link. In case of the issue is only related to your boss’s account, please also provide us the tenant information via the private message link.
Thanks,
Rena