I'm making a mod that involves modifying a global BHAV (0250: Pregnancy - Try to Get Pregnant). I am not convinced it is doing what I want it to, so I am trying to get it to display some of the values it is using so I can work out what is going wrong. But even when I add a step that is supposed to display text, it doesn't happen.

Any suggestions about what I can do to make the game tell me what it's up to?

The dialog type that can be used in most contexts is Text Notification because this dialog is instantaneous. Be careful not to show too many notifications in a loop. They will unfold for ages. When called from a global context, the strings have to come from the global group D46CD0. I would often use the string "My ownership is $Local:0". You can also find a string that will show $Me and $Object.

A way to use other strings is to set up a holder object and use Tree By Name (name is again from global scope, such as CT - Display Balloon. It requires a preparation to modify or make this object. Then you have to pass on parameters to it instead of referring to locals that were in the context of the parent script.

As it turned out, the issue was that I forgot to delete the original mod I made mine from, and it was being overwritten. But thank you for the advice.

A different mod I have added extra strings to Globals dialog, so I added some more to say "Local 0 is $Local:0" etc., which was very helpful for checking that the mod was behaving itself.