Hunter? Is it possible, YOUR training center certifications aren't high enough? Like, say for example your horse is ranked at National level, but you only have the certification up to State level? That's one possibility, I can think up of, you need to up your certification level.

As for therapy? Well, do you have a Therapy center bought? I never tried out the other Careers, as most just stick with the Model horse one, as you start off with that and any others, takes up precious estate land, which plenty of folks, prefer to use the land for stalls instead.

Now, for Therapy, I 100% cannot say this is NOT the issue for your Therapy career training, and someone else can come in and correct me on this front and the other one too, but these are the only two possibilities that I could think up of, that could be wrong.

I do have all the Training Centers, etc so I have the ability to train Therapy.

If the issue is level of the center, it'd be a great idea for it to indicate that and not say I just don't have the center needed. It's really confusing.

So, you do own a Therapy Center? A Therapy Center is completely different from an actual Training Center and needs to be bought/purchased as a separate building from the Construction part of the game.

Could you take a screenshot of the Career Center page, where you have Therapy Center unlocked and post the link here?

That would be nice yeah, could be a feature request added in.