You can set maximum number of values users can enter for this field to be one.

Go to admin >> select the field from content type >> update the number of values

If you want to keep this settings as unlimited then you can use form validation function.

Thanks,

On Wed, Jan 14, 2015 at 9:01 AM, Nancy Wichmann <nan_wich@bellsouth.net> wrote:

I have a file field that has unlimited cardinality (and needs to). But I need to only allow one upload per submission. Does anyone know how to do this?

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Thanks
Muhammed Naushad
Web Developer
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