We're receiving reports that other users are getting this issue as well, gary74.
I've checked and verified that we have reported issues with other users being unable to view the reconciliation report in QuickBooks Online. We've already submitted a ticket about this issue and our engineers are all hands on deck working together for an immediate fix to sort everything out.
While they do, I would advise you to get in touch with our QuickBooks Support. This way our engineers can add your account information to the list of affected users and attach your case to INV-55849. Any progress will be communicated via email.
Please be reminded that our Support Team is available from 6:00 AM until 6:00 PM on weekdays, and 6:00 AM till 3:00 PM on Saturdays. Here's how to contact or chat from us:
1. Click the Help (?) icon.

2. Choose Contact Us.

3. Enter a brief description of your situation in the What can we help you with? area, then click Let's talk.

4. You'll be presented with a few options for connecting with Intuit. Select Get a call.

In the meantime, you can always visit our Help Articles page for QuickBooks Online in case you need some reference for your future tasks.
Please extend your patience while we're working on the permanent fix. Don't hesitate to drop me a line if you need other help with QuickBooks or have follow-up concerns in mind. I'm always here to make sure you're covered. Have a good one.