I've got instructions to share on how you can get past the error that you receive when creating estimates in QuickBooks Online.
Once you encounter unexpected behavior in QuickBooks, it's recommended to perform the browser troubleshooting. This helps determine if the issue is browser related. You can start with accessing your account through a private window and process the estimate from there.
If you haven't received an error, I suggest clearing the cache of your regular browser. Cache is stored in order to speed up loading times. But this can impact the system's processes and may lead to the error that you receive. To give you complete details on how to do this, please see this link: Delete or Disable Cache and Temporary Internet Files in Your Web Browser.
You may also these links attached below about managing estimates and on how convert them into an invoice for reference:
Get an error message in Estimate when we start to type name.
Good afternoon, linda84.
Could you describe the error you're receiving? Is there a number associated with it? A screenshot of what is happening would be the most beneficial, that way we can help troubleshoot the issue to the best of our ability.