If you are trying to modify a SharePoint form using InfoPath and your data connection is exceeding the default limit of 1500 kb then you will probably get the following error:
To solve this:
- Open Central Administration.
- Go to General Application Settings > InfoPath Form Services > Configure InfoPath Form Services.
- Click on Data Connection Response Size. By default, it is 1,500 kilobytes.
- Change the Response Size in kilobytes (increase it).