Hi there! Thank you for posting an inquiry to the Microsoft Office Community. My name is Darhyl and I'd be glad to help you out!
I'm sorry you are experiencing this with your account.
Based on the error message you provided, kindly try to perform the following workarounds according to this article: https://windowsreport.com/microsoft-account-doesnt-exist/
"1. Check if the account name was typed correctly.
It is possible sometimes that, the account name was misspelled. Double-check if you typed it incorrectly.
If the account name was typed correctly, maybe the email address is incorrect or has been changed recently.
Make sure that your email has the correct domain at the end: @gmail.com, @outlook.com, @live.com, etc.
Try to log in using your old email address or phone number if they were changed.
2. Find your account name from your Windows 10 PC or Xbox.
Click on the Start button on the left side of your Taskbar, and select Settings.
Head over to Accounts, then Email & accounts.
Check your Microsoft account names under Email & accounts.
Another method would be to open any Office 2016 or 2019 app and create a new document.
Click on the top left corner where it says File, then select Account.
You can see your Microsoft account name under User information or in the Product information section.
One last method would be to sign in to your email associated with your Microsoft account.
Then, check for previous emails from Microsoft.
The previous emails from Microsoft will show your account name.
3. Make sure you’re using the correct account type.
An account that your workplace or school provided may not have a Microsoft account associated with it. So, you might need to create a new Microsoft account.
Normal accounts can be used for logging in for one or more services, such as Outlook or Microsoft 365.
Work or school accounts, however, cannot be used to connect to other Microsoft services, such as Xbox. Additionally, an Xbox Gamertag cannot be used to sign in to a Microsoft account.
The only valid ways to sign in are by using an email address, a Skype ID, or a phone number registered to the account."
4. Your Microsoft account might have been compromised/hacked.
From the official Microsoft article: https://support.microsoft.com/en-us/account-billing/how-to-recover-a-hacked-or-compromised-microsoft-account-24ca907d-bcdf-a44b-4656-47f0cd89c245 try to follow the instructions in the interactive tool in order to recover your account.
Thank you for your kindness and understanding! Please feel free to let me know if you need anything else.
Best Regards,
Darhyl
