I can't update the Actuals

[Newbie]

Hello,
Everything worked fine during sevral months, but today, as administrator, I
can't update anymore the Actuals that I'm receiving from
the resources timesheets. When I click on the Update button, I get the
message:
"Project Server error:
The server returned an error. The error could be triggered by the following
reasons:
- the specified URL is not valid
- Internet Explorer is set to work offline
- The server can' process your query
- An internal error occured on the server"

Then, when the process is going on, I get the message:
Updating error in Project. Project is actually running with a profil which
doesnot match your PWA connection".

This last statement is false : Project was not running at all....

Thanks for your help