The file "Unity-IPhone.ipa" couldn't be opened because there is no such file"

Hi,

This is the message I receive from xCode during the export for a Enterpise deployment distribution.

I have the certifcate for distribution, the appID, the Provisioning Profile but I receive always this error.

It's the first time I try to do this Export then surely I'm doing something wrong. But What?

Please, any help?

Thanks