If MaxSubscriptionCount is set, the test produces too many sessions and it fails.

Add lines to the test init to cap no of sessions if server doesn't support so many subscriptions:

/ Test prepared by Shane Kurr : shane.kurr@opcfoundation.org;
Description:Create half as many sessions as are claimed to be supported; e.g. create 5-sessions if the Server claims to support 10. For each session,
create half the maximum number of subscriptions allowed, with 1 monitored item each. Then, call Publish once per subscription, per session. /

// Set Constants
const SUBSCRIPTION_COUNT = 5;
const PUBLISH_QUEUE_SIZE = 5;

// Get number of sessions and subscriptions from settings, set constant
var SessionCount = Math.ceil( Settings.ServerTest.Capabilities.MaxSupportedSessions / 2 );
if( SessionCount == 0 ) { print( "Forcing # sessions to 5." ); SessionCount = 5; } // arbitrarily set session count to 5.

// add these two lines to 003.js
var SubscriptionCount = Math.ceil( Settings.ServerTest.Capabilities.MaxSupportedSubscriptions / 2 );
if( SubscriptionCount != 0 && (SubscriptionCount / SUBSCRIPTION_COUNT) < SessionCount) { SessionCount = SubscriptionCount / SUBSCRIPTION_COUNT; print( "Adjust # sessions to " + SessionCount); } // adjust session count.

const PUBLISH_CALLBACKS_NEEDED = SessionCount * 5;