My tutorial is now running the way I want it to, although I get the error message below with each dialog. Are you able to determine from the error what the issue is?
NullReferenceException: Object reference not set to an instance of an object
TutorialDesigner.Dialogue+<TrackDialogueVariables>c__Iterator0.MoveNext () (at Assets/TutorialDesigner/Scripts/Dialogue.cs:812)
UnityEngine.SetupCoroutine.InvokeMoveNext (IEnumerator enumerator, IntPtr returnValueAddress) (at C:/buildslave/unity/build/Runtime/Export/Coroutines.cs:17)
TutorialDesigner.<Work>c__Iterator0:MoveNext() (at Assets/TutorialDesigner/Scripts/StepNode.cs:551)
what's the dialogue GameObject you are using? It could be that you use some that are using TextMeshPro but didn't load the module into TutorialDesigner:
Window -> TutorialDesigner -> Load TextMeshPro Module
Or did you create the dialogue objects yourself?