Failed to import image : Image file does not appear to be an ISO 9660 CD

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Hi! I try to import:

FreeNAS-9.3-STABLE-201501301837.iso

http://www.freenas.org/download-freenas-release.html

But i get this error:

Failed to import image : Image file does not appear to be an ISO 9660 CD - format was detected as x86 boot sector

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