Second, let's make sure to update your QuickBooks to have the latest features and needed patches. If the same thing happens, you can open a different or a sample company file to test if you'll get similar results.
To open a sample file:
Open your QuickBooks, and run it as administrator (Right-click the QuickBooks icon, and choose Run as Administrator.)
On the No Company Open screen, select a sample file from the Open a sample file drop-down.
Then, access the said option again to enable your online services.
If the said option works this time, then the original file might be damaged. In this case, I recommend running the QuickBooks Verify and Rebuild tool. This can help identify and repair data issues.
Here's how to Verify your data (original company file):