People masks not working properly after update

I had the same AI Person Mask error, with no people detected. I suspected it was the blur AI interfering which I normally use last in my workflow (usually pulling masks by habit before applying the blur). I turned off Blur AI off, and the person detection worked fine. Try that. This is the 13.2 version of LR and Mac OS 13.6.1 for anyone who is from Adobe seeing this.

Yesterday I got further evidence of LR weird behaviour. It's something I had ocassionally noticed in the past, but now it seems much more acute.
On the other hand, there's an easy trick that can be used to overcome the issue.
When I asked LR to apply a "select people" mask in this picture, it returned the dreaded "No people found" message, so I was stuck with the much less detailed "subject"

But, once I rotated the image so that the person appears upright instead of horizontal, not only it did detect people, it even distinguished between the main image and its reflection, allowing separate adjustments.

I haven't tried yet with other angles, for example 45º (I guess I'd have to pre-process the RAW file in PS, because LR doesn't allow "cropless fine rotation"), but I'll report results if I do.
In summary, position does have an important effect into LR AI people recognition capabilities, and "straightening" them can make them recognizable.

@Fernando35436819506j 

I had the same issue.

The new algorithm is sometimes but not always failing to detect People, or some parts of them, while the older algorithm was able to select them.

As a workaround you can use Objects tool to select the individual parts of the person when People fails to detect them.

• Despite what LrC says many times "Updating Ai Settings" will not make any difference and the "updated Mask" is identical to what it was before so you can simply keep the masks as they are and ignore the update warning.

In any case you can go back in history and revert back to when the People' selections were available. 

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Attach one of the problem photos here or, if the forum won't let you, upload it to Dropbox, Google Drive, or similar, and we can see if the problem occurs in other LR installations. That will guide further troubleshooting.