Check database, in table "project" you'll find all projects.

Possibly you just "do not see" projects, but thy are here.
Check rights definition and profile of allocation to projects.
Admin should see all projects 😉

more precisly,
some users didn't see tasks added under projets.
where i have to look at ?
thank you in advance
 

Access rights !
(RTFM)

unfortunatly, rights are correct. In admin mode if I made a search about these activities, i found nothing.
Thoses activites are lost in the database ? how can i verify that ?
Thank you

Hi,

Look into table ... activity (for activities).
If you look for tickets, look into table ... ticket
I think you can guess in which table you will find milstones ...

Ok, It was totally not the update.
an user was closed(deleted) few weeks ago and theses associate tasks was closed too...
Sorry for that