Pet talents cannot be spent in any way, despite attempting to spend the points after enabling (check box) the edit button.
You also cannot create a pet talent template.

Talented v220907

Do you get any error codes? I was able to create and edit pet talent templates just fine, but I haven't tried to spend talent points with an actual pet (I will test this).
What language is your client?

Do you get any error codes? I was able to create and edit pet talent templates just fine, but I haven't tried to spend talent points with an actual pet (I will test this). What language is your client?

No error codes or I would provide them. If this changes I will of course update this post.

Tried with both a cunning (Wind Serpent) pet and a Ferocity (Devilsaur) pet. In both cases I had to disable Talented addon in order to spend talents. Interestingly there seems to be a Blizzard issue as well. Disabling Elvui and Talented with a cunnin pet, the second ability Dive as well as the 2 talent ability chained directly below it remain grayed out even though the talents do get spent. They also show 1/1 and 2/2 respectfully while remaining grayed out.

Client language is English.

Yeah, can confirm templates can be created no problem, but the talents can't spend the actual points.

I will give this a look when I get a chance, but life is particularly busy - you may need to hold onto your bowstrings for a few days

No problem, but something I observed, not sure if it is related. On my pet talents, it says there is 13 unspent talent points, but as lvl 23 pet, it should have only 1 point, which is spent already.

I may open another issue about this if that would be better.

Edit: I am taking a look as well, because I have a hunter lvl 20+ with a pet, I may be able to do some tests. It seems there is something wrong with how the addon checks for the pet talents (spent and available).

I am still looking for the reason of not being able to spend points, but I think it is related with the message I mentioned, the addon seems to be trying to use the character functions to work with the pet talents. (For example, there is a function GetPetTrainingPoints, which returns the current total and trained points of the pet, but the addon uses GetUnspentTalentPoints to all talents.

Edit 2: I am not too used to Lua, but I can't find the declaration of Talented:OrderedLearnTalent anywhere in the code to try to debug the call it makes to LearnTalent, any tips?