Hi there! I've been using the ace_medical_fnc_treatmentAdvanced_fullHeal to fully heal players using an addaction, just like this (pretty standard):
this addAction ["<t color='#fb0000'>Recibir tratamiento medico</t>","call ace_medical_fnc_treatmentAdvanced_fullHeal"];
The thing is, since the last update that function doesn't work anymore. This is the error that I'm getting. Did it get replaced by another one?

That function was never public, so always subject to change. It is now named differently:
https://github.com/acemod/ACE3/blob/master/addons/medical_treatment/functions/fnc_fullHeal.sqf#L14
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That function was never public, so always subject to change. It is now named differently:
https://github.com/acemod/ACE3/blob/master/addons/medical_treatment/functions/fnc_fullHeal.sqf#L14