typedef changes affect all sub .vi's, and earlier versions of my main .vi no longer run

[Mountain_Matt]

I use typedefs so that a single programming change will propagate throughout the main .vi. as well as in every sub .vi in the main .vi.  My problem is that when I make a change to a typedef, earlier versions of my main .vi no longer run because the typedefs in their sub .vi's are changed.  What am I missing?

[altenbach]

What is the error message? What kind of changes are you making to the typedef?

[Mountain_Matt]

Suppose I add a new Control to an existing typedef.  Now the main .vi and every sub.vi with that typedef gets updated.  This is great for the current version of main .vi.  But older versions of the main .vi (which I still want to use) now have sub .vi's which are no longer compatible, since the updated typedef in these sub .vi's now has an additional Control.

Thanks for your willingness to help.

[RavensFan]

So you want to make a new version of your main VI, but still have a functional "old" version of the main VI?  Why would you want to do that?

It sounds like you are creating a branch of your code base.  If you are going to do that, you should just cut the branch of  completely.  Make a complete copy of your VI hierarchy and create a whole new project from it.  If necessary, rename the typedef and make a different copy of it with a different name so that you don't confuse it with the "old" typedef.

[Mountain_Matt]

I want to keep a functional copy of my old version because that version is being used by someone.

One problem I have is I don't completely understand how Projects work.  I should do some researech on this.  I do rename my typedefs, but when I Apply Changes to the newly renamed typedef, it changes all the typedefs in the main .vi as well as all sub .vi's. 

I'll look into your suggestion to "Make a complete copy of your VI hierarchy and create a whole new project from it."

Thanks