This thread is resolved. Here is a description of the problem and solution.
Problem: WordPress caught an error with one of your plugins, WPML Multilingual CMS.
Solution: Go to WPML-> Support ->Troubleshooting and click the below buttons:
+ Clear Cache in WPML + Set Language information + Fix element types collation + Remove ghost entries from the translation tables + Assign translation status to duplicated content + Set language information
This is the technical support forum for WPML - the multilingual WordPress plugin.