I believe this error is caused due to MySQL version 5.7 is installed on your server. There's a fix for this issue in the works (https://github.com/Elgg/Elgg/pull/10121). You might want to try if your Elgg installation works after modifying the file engine/classes/Elgg/Database.php as shown in the pull request. Hopefully, the next release of Elgg will contain this fix already for Elgg to work on MySQL 5.7 out of the box.

You made my day :)

It works, many many thanks

D

I've merged the PR and 2.2.2 will have this fix.