Update project description from web site doesn't work

error in the logs : tx_nG6_eid update_db_field 14-08-18 08:00 - Core: Exception handler (WEB): Uncaught TYPO3 Exception: Too few arguments to function tx_nG6_db::update_field(), 4 passed in /save/ng6-test/src/ng6-git-gsalin/ui/nG6/class.tx_nG6_eid.php on line 266 and exactly 5 expected | ArgumentCountError thrown in file /save/ng6-test/src/ng6-git-gsalin/ui/nG6/lib/class.tx_nG6_db.php in line 47. Requested URL: http://ng6-slurm.toulouse.inra.fr/ng6-mmanno/index.php?eID=tx_nG6&type=update_db_field&table=tx_nG6_project&field=description