The European regulation since 2015 on international successions provides that it is the law of the country of the last domicile of the deceased.
But for Morocco, Moroccan law is not applicable to the deceased because it does not come under the conditions provided for by Article 2 of the Moroccan Family Code.
Ain, he is not Moroccan and is not in relation with a person of Moroccan nationality.
There will therefore be reference to French law. French law will apply to all its movable property, immovable to France, Morocco and all other countries where it would have property.
For mixed marriages, the foreigner will have to convert to Islam in order to marry one or A Moroccan woman. In this case it is the Moroccan Muslim law that applies.
If there are children of a first marriage in France they will not be able to inherit the Moroccan good think to foresee your transmission by a donation for example and a will international.
A new advantage to settle in Morocco, there is no « inheritance tax » to pay, which is also very attractive to transmit your goods with serenity.