ECHA published advice on how to avoid the most common business rules failures. The <link https: echa.europa.eu support registration from-submission-to-decision _blank>latest advice on these common business rules failures that happen during dossier submission in REACH-IT also contains information on why they happen, and what you can do to avoid them. As these particular failures cannot be detected by the Validation assistant in IUCLID, it is important that you pay attention to them.

Also, have a look at the <link https: echa.europa.eu support qas-support browse qa view scope reach-it _blank>Q&As on the most common business rules failures.