I migrated my site to a new server and did an update of zenphoto
But my gallery is not showing in the migrated site
old site: http://www.michel-nulens.be/page/gallery
new site test url) http://michel-nulens.amstudios.a2hosted.com/page/gallery/

Sure you followed the instructions here https://www.zenphoto.org/news/installation-and-upgrading/#--moving-existing-installations and the linked page within?

Are the albums published?

the albums are published, all other pages where displayed, just not the gallery

Do you have the latest version of the zpArdoise theme installed?
Did you set the "Homepage" option in the theme's options?

that is the solution! Thanks!