This thread is resolved. Here is a description of the problem and solution.
Problem: I am getting this error:
We have detected a problem with some tables in the database. Please contact WPML support to get this fixed.
Solution: If you have WPML v4.0.7 or earlier, it is safe just to dismiss that notice as it could be a one-time event due to updates, all will be fine for WPML then. We had a similar issue before, but it was handled already in the current version. You see this error since you are just upgrading from the old version (which produced that error) to the new one.
In case you can’t dismiss this notice, you can solve it by removing the empty value from your database table "wp_icl_strings" using database tool like PHPMyAdmin or similar. Before doing that please Backup your database and website for safety.
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