Open Manage Network Manager lets you fine-tune various features of the application. Rather than lose those changes if and when you upgrade your application, best practice is to override changes. To do this for the web portal, first rename the provided file \oware\synergy\conf\server-overrides.properties.sample to server-overrides.properties, and enable the properties within it by uncommenting them, and altering them to fit your needs. The comments in this file provide more information.
You can also override application server-related properties in \owareapps\installprops\lib\installed.properties.
Both of these properties files remain as configured if you install an upgrade, but upgrades overwrite the server-overrides.properties.sample, so keep a copy if it has anything you want to preserve.
Screen names -- A new property requires a minimum length for user screen names. For the existing user base then any screen names that are shorter than the value must change to the required length on the next edit/save for that user.