Firstly, I'd appreciate it if you could update WPML plugins to the latest versions as you use old versions of WPML Multilingual CMS and WPML String Translation.
- IMPORTANT STEP! Create a backup of your website. Or better approach will be to test this on a copy/staging version of the website to avoid any disruption of a live website.
- Go to "WordPress Dashboard > Plugins > Add new > Commercial (tab)".
- Click the "Check for Updates" button.
- Update WPML and its addons there.