Hi Tonydotigr,
Even I had the same issue. I am able to resolve it. The reason for getting such error message is with the Form library limitations.
To solve this issue, perform these below steps.
1. Open Form library where you published your Infopath form.
2. Go to Modify View option.
3. Go to Item Limit. There you will find the Text box.
Change the item limit option according to your requirement.
That will resolve your issues.
Regards,
Basha