I want to make sure your file conversion is seamless, @Migrating to On-Line Problem.

When you want to covert from QuickBooks Desktop to QuickBooks Online, you need to have the desktop updated to the latest release. Before anything else, may I know what version of QuickBooks do you have? You may check the current release from the following:

• Release notes for QuickBooks Desktop 2020
• Release notes for QuickBooks Desktop 2021
• Release notes for QuickBooks Desktop 2022

If your current company file is not updates, you can manually install the update patch outside QuickBooks and see if it makes a difference. See these steps:

1. Go to the Downloads & Updates page.
2. Choose US for the country.
3. Below the survey, click on the standard setup link.
   
4. On the next page, enter your QuickBooks version to update then press Search.
   
5. To download the patch, click the link for Get the latest updates.
6. At the bottom once the patch is downloaded completely, wait until it launches automatically. You can also double-click on it to apply the update. See this sample screenshot:
   

After updating file, you can follow these steps to start the conversion process:

1. Make sure to sign in as an admin to the desktop company file you want to move.
2. Press Ctrl + 1 to open the Product Information window.
3. On your keyboard, press Ctrl + B + Q, then select OK to display the export window.
4. On the export window, select Get started.
5. Sign in as an admin to your QuickBooks Online company.
6. Use Choose online company, then select the QuickBooks Online company you want to replace with your company file.
7. Click Continue.
8. If you track inventory in QuickBooks Desktop:
   • Select Yes to bring them over, then specify the as of date.
   • Select No if you want to set up new items later in QuickBooks Online.
9. Add the keyword “Agree” in the text field, then select Replace.
10. Select Yes, go ahead and replace the data, then select Replace.

I've included some related links to aid you with the conversion process:

• Migrating from QuickBooks Desktop to QuickBooks Online
• Move your QuickBooks Desktop file to QuickBooks Online
• Move from QuickBooks Desktop to Online

If you're still unable to convert, I highly recommend contacting our Support Team for assistance. They can help you transfer your file successfully. Here's how to contact our Technical Support:

1. Open QuickBooks and click the Help menu.
2. Select QuickBooks Desktop Help.
3. On the pop-up screen select Contact us.
   
4. Click the Search for Something else button then type your concern in the Ask us anything box.
5. Hit Search then scroll down to get your contact options.

Refer to this article to learn more about our contact options and support availability: Contact QuickBooks Desktop support

I want to ensure everything is resolved for you. Post here again with the result as I want to know that this has been taken care of. I'm also here to provide further assistance if you need further help.