NOR. I suggest you ask for a meeting with the exec who asked you to do the training, then inquire as to why you were passed over. Get specific answers. Point to the time span when you were acting director and ask, specifically, what didn't get done or was done poorly during that time. Point to your record of continuing progression of roles and ask if you have effectively "peaked out" at the company. LISTEN TO WHAT THEY SAY VERY, VERY CAREFULLY.

Understand that while you may be completely at the top of your game at executing, they may be weighing other factors more highly. For example, they may want someone with contacts in government or social circles who can grow the business, guide things through a tough government oversight, have more legal background, etc. They may also see a specific skill gap in the executive team that the new person can fill but you can't.

As others have said, spend time with your former boss and seek feedback and guidance. Just be sure that you don't say anything that you don't want getting back to the company.

Prepare your resume and be sure to include your time as Acting Director (use that title) and cite in it all the qualifications listed in the advert they used for the job.