Hi,
few comments already
- Is there a place where viewers will be able to download them scenes to further study your examples?
Part 2:
For the event "go", instead of trigger it via the fsm canvas, simply have it as a global transition over the state and mark the event "go" as "show in inspector, and then you can trigger processes right from the Unity inspector of that PlayMaker component.
Part 3: Why using a breakpoing on each state instead of stepping through with the debugger? just set a breakpoint on start state and then simply step through.
also, for catching errors, a vers good trick is to have a state with its name set to an empty string ( as many spaces as you want to have them uniquely named) and then put a breakpoing there, it will always be available if the error is triggered amd won't affect trouble free processes.

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in general, if your xml turns out invalid, simply use online xml checkers to find where you have a typo or a wrong structure, it's very easy to mess an xml file when you edit it without a dedicated editor
http://www.xmlvalidation.com/for testing xpath, I often use
http://www.xpathtester.com/xpathI'll be editing the datamaker wiki and put links to your videos and all. Thanks again for your work on this!
Bye,
Jean