library\Base\Objects\monitoredItem.js: 488ff:

function: setValue()

For arrays of BuiltInType.ByteString the creating of UaByteStrings() is missing:

current:
<code>
case BuiltInType.ByteString:
node.Value.Value.setByteStringArray( newValue );
break;
</code>

proposed fix:

<code>
case BuiltInType.ByteString:
var x = new UaByteStrings();
for( var i=0; i<newValue.length; i++ ){ x[i] = newValue[i]; }
node.Value.Value.setByteStringArray( x );
break;
</code>