1. To ensure the quickest and most accurate support, please provide your debug information so that I can get a look at some of your configurations. You can find it in WPML > Support > click on “Debug information” link. Please check this link for more info: http://wpml.org/faq/provide-debug-information-faster-support/
2. I've enabled the private reply. Please provide us with the duplicator package download link once it's ready.
It seems to be a conflict issue between WPML and the latest version of the "Site Kit by Google" plugin. We got a few reports from other clients with the same error.