Dear Dineth,
Good day! Thank you for contacting the Microsoft Community. We are here to assist you
I'm sorry to hear that you're having trouble in editing file as it is opening in view only mode. To better understand the issue, we kindly request some additional information. Could you please provide the following details:
- Are you using Microsoft account (like ******@outlook.com or other email addresses) or work/school account (like ******@domain.onimicrosoft.com or ******@domain.com)? If you are using work/school account, are you signed in the browser with same account?
- How does he/she share the workbook with you, send you an edit link of the file or you receive an invitation email for the file? Let that user create a no-sign in required (Edit) link, share that link with you. See if you can edit the workbook.
- Are you able to edit the file with Excel desktop app, do you edit a copy of the file or the original file? When you access Excel Online with your Office 365 account, are you able to create files, edit files, save files?
- As you mentioned it was working fine a few weeks ago can you check if your subscription is still active by accessing "My Account"? please share screen shot with us.
Please understand that our initial reply may not always immediately resolve the issue. However, with your help and more detailed information, we can work together to find a solution.
Have a great day and take care! 😊
Sincerely,
Naren | Microsoft Community Moderator