If you save system property with a text containing newline (not \n or br). It will save that correctly. But when you try to edit that property it displays <br> tags. You have to delete them every time when editing the property, because Admin Console will add those tags to the property string.
Is this bug still ocuring for you?
Can confirm it for Openfire 3.6.3
Removing the 'fix version' for all unresolved issues that were scheduled for version 7.8.2. We're releasing this version today - the remaining issues should be rescheduled later.
This is still valid
Patch under review (courtesy Peter Johnson).
Applied patch and performed light testing via admin console. Presumed fixed.