Solved for us, with updating WPML core to 4.1.2 as suggested.
Hi there,
we are facing a similar issue, only thing we did to our site was updating:
BackWPup 3.6.6 on Nov 29
wpml-media-translation 2.4.0 on Nov 29
wpml-string-translation 2.9.0 on Nov 29
wpml-translate-management 2.7.0 on Nov 29
sitepress-multilingual-cms 4.1.0 (WPML core) on Nov 29
contact-form-7 5.1 on Dec 11
Last successful backup was on Nov 29 in the morning, all backups starting from Nov 30 have failed due to the WordPress XML export logging the error mentioned by julia0902
I have to admit, that we might have updated from an older version for each of those plugins (so we might have not run on “n-1” versions, but rather updated from “n-2” or “n-3”)
