Signos de admiración en amarillo y Consulta sobre máscaras, ambos en cCamera Raw

What does the yellow alerts mean? And what should I do about it?

By @josantgomez

There seem to be different meanings according to context. i.e. what sort of layer it is.

It could indicate out of gamut colours, or if iot is a text layer, it could mean that the layer is using a font that is not installed on that computer.

2nd Question, masks.

If I hover over a mask, an overlay appears that informs of the accepted selection. If I don't hold the cursor, the selection is no longer visible. 

In order not to have to make a new selection like this, what should I do so that it remains according to the mask and can make adjustments in the selected areas?  (I repeat that if I remove the cursor, the selection is no longer visible.

By @josantgomez

What colour is the overlay, and what tool are you using when you see it?

If magenta, then you might be using one of the Ai selection tools.

If blue, then it might be the Free Transform box and handles, or it might be the fairly new layer bounds indication that you can turnm off in the Options Bar.