The Simplicité Instance Manager (SIM) version 5.18 has been released.
This version prevents instance name to use underscore character _ due to new hostname enforcement rules applied by Tomcat versions above 8.5.31 and 9.0.8.
ACTION REQUIRED:
If you have any existing instance name with underscore character, make sure to rename it with a strict alphanumerical name (the hyphen/minus character - is already forbidden due to PostgreSQL naming policies). If you don’t do so Tomcat will return a HTTP 400 error.
See this document for details on the SIM usage