Infopath Form – Edit Mode – Error related to list view threshold in SharePoint Online

I have an Infopath 2007 Form.
When I open the edit form(already saved form) , I am getting the below error:

The query cannot be run for the following DataObject: MyFormGetInfo InfoPath cannot run the specified query. The SOAP response indicates that an error occurred on the server: Exception of type 'Microsoft.SharePoint.SoapServer.SoapServerException' was thrown. The attempted operation is prohibited because it exceeds the list view threshold enforced by the administrator.0x80070024 

I dont get this error when I open a new form , make some updates and save it for first time.

Once a form is saved, when I open the Edit Form only then I see this error.
Inspite of this error, I still can make updates to the form and data is saved.

Can anyone suggest how to get rid of this?

Since this is SharePoint Online, we cannot change the listview threshold. Please suggest! Thanks in advance!