Hi i cannot see the title and description in the photo popup that i've reported in the Editing Gallery panel as your instructions report to do it.
In the admninistration i've set up the "Default caption (label) handling" on "Read contents of caption files"
I've also checked the it-IT.labels.txt in the corrispective images folder and it is correctly compiled (with the title and description i've inserted in)
Why i cannot see title and description in the pictures popup?

Hi,

Are you sure that you edited the captions of the correct gallery? Is there a link to the page with the issue?

yes i think so
the url of the page is www.jayasatyayoga.it/galleria-fotografica/asana.html
i put this tag in the page {gallery}/media/jw_sigpro/users/0000000287/Asana:250:160:0:0{/gallery}
in the administration i put title and description of the first image /media/jw_sigpro/users/0000000287/Asana/_DSC2188.jpg

this is what reported inside the file it-IT.labels.txt on the first line:

_DSC2188.jpg|Prova|Prova descrizione

but nothing is shown...

You are using a gallery snippet which disables the captions. Please read carefully the section named "Manual Gallery Snippet Setting" at the documentation page at www.joomlaworks.net/support/docs/simple-image-gallery-pro .

Let me know if you need more help.

yes i read on the manual about the settings but even if i set on the Gallery Settings "Display Mode" and "Caption mode" on the way i need, this settings din't remain confirmed and recorded and i cannot see a Save button or i imagine that when i close the popup administration window the setting is saved.

At the moment i resolve by managing the Manual Gallery Snippet Setting reporting the "caption_mode" field on "2"

Can you provide more details regarding the missing save button? The save button on the settings page is available at the upper right corner of the screen. When you edit a gallery snippet, there is no specific save button targeting the gallery, you just need to save the article.