Where do you get this error?

can you please post the full error messages?

Does the auto archiver cron work for you?

Error Unable to write in the cache directory (/xxx/tmp/templates_c/be/4c,) This error occurs when sending email report.
General statistics "all websites" do not work (except with the Allow Piwik archiving to trigger when reports are viewed from the browser, but the error sending mail is always present).
Actually self archiving by cron job is running hourly.
These errors appeared after the updated 2.2 automatically

MAJ 2.2=>2.2.1
Same Problem (for information)

After the MAJ 2.1=>2.2 the directory concerned had no owner.

modification made to the rights and auto archive updated at cron tasks, all seems ok now.

So it is fixed now? Which directory had no owner?

Do you run the auto archiver with the same user as the webserver does?

Hello, everything is settled now. Some temporary files had no owner in the directory / tmp / templates_c / be /. These directories have been modified to have the proper owner.
Cron tasks were run with admin rights, and I have changed with the appropriate user who runs the site (multi configuration website and multi-user on the server)

Thanks for feedback