When running an import in uSync for the settings, one of the content types fails. uSync tries to add an item, with the same key, twice to the content type. This is the error.
Version 17.0.2 was released that has the fix. However, I don’t see a v16 bug fix and I don’t know if 16 will be patched as well. I hope so, since we can’t upgrade to 17 just yet. @KevinJump ?