I use the
vbnewline command in the expression field, I have had minor trouble in the past with the overall display of some labels, but the majority would display correctly. I do believe it is one of two things, you either need to double check that the VB code you entered is entered correctly or your settings in your placement properties are interfering with your vb code in your expression.
Here's what I have for my expression:
[NAME] & VBNEWLINE & [PID] & VBTAB & "(" & [ACREAGE] & ")" & VBNEWLINE & [file_as_na]
You also want to make sure this checkbox is unchecked! see below:
Then in your placement properties you need to make sure the options for stacked labels are on.
Lastly it produces a labeling system like this:
maplex options under placement properties you can assign the 'force split' to create new lines in a label. This typically works well if you have attribute fields that are very long and need to be broken up, or if you have merged fields like addresses that can be be broken down at comma points. Most of my data is contained in fields with shorter text entries, therefore I like using the VBScript option so that I can tell it to separate by parenthesis and add four or five different fields. There may be equivocal options in the Maplex tables. The Maplex options may be quicker to assign and set up, but offer less overall control or customization than the VBScript expressions, a mix of both might be best in the long run.
Hope this is what you were looking for, and I hope it helps,