Contribution plugin-user info

I am getting this error when I try to contribute (without being signed in as superuser) "Could not retrieve user info." In the superuser side, an item is created but there is no title, image, description, nothing that I put into the contribution form. Oh, and I am using the "simple" option.

If the error page includes more info -- like a long list of gibberish-looking lines of info -- could you include those? Thanks

Unfortunately I don't get any more information. I can see detailed errors other times in the back end, but when I try and add something as a non-superuser I just get that simple error message. On the superuser side I get NO error message. An item is created with absolutely no information or image etc.