Document Set Form Error

We have a library with a Document Set and have used Forms Designer for the Properties. Although the form works sometimes, we keep getting the error Something went wrong. To add an item to a document library, use SPFileCollection.Add()

I’ve completely rebuilt the form and am getting the error again. Any ideas?

Thanks,
RKeener

Hello, RKeener!
Can you please show us where exactly you get this error? Right now, we can’t be certain what you do and where exactly the error appears. A screenshot and a brief explaination would do nicely!

We have a library with a document set that has a Forms Designer form. The first time someone submits it works. Subsequently, with equivalent data when they click save the get the following error:


Thanks!