Hello Jérémy,
Thank you for the detailed description. Here are the checks, in this order:
1. In the web interface, open the Administration dashboard and look at the Scheduler widget. It lists each Scheduler registered with the database, with its version and a "Last updated" time (shown as, for example, "20 minutes ago"), which is when its last heartbeat was recorded. Hovering over a row whose status is Down shows the reason given for it. Please take a screenshot of the widget now, with that tooltip showing.
2. Turn on the Scheduler's log file. In Administration > Server settings > Logging, make sure "Log debug information" is checked and set a "Scheduler log path" to a folder that the account running the Scheduler service can write to. Save, then restart the Scheduler service. The steps are under "Enable Scheduler logging" on this page:
https://docs.devolutions.net/server/knowledge-base/knowledge-base-articles/scheduler-service-general-information/#enable-scheduler-logging
3. Two minutes after that restart, refresh the dashboard and take a second screenshot. A running Scheduler updates "Last updated" every minute, so if its row still shows a time from before the restart, no heartbeat has been recorded for it since. Please also tell us whether any log file has appeared in the folder you set.
4. About five minutes after the restart, open the Devolutions Server Console (close and reopen it first if it was already open), go to the Support tab, click Generate Support Package, select every log it offers, and attach the .zip to your reply. The package only collects the Scheduler's log files from the Scheduler log path the Console had loaded, which is why it has to be reopened after step 2:
https://docs.devolutions.net/resources/customer-support/generate-a-support-package-in-devolutions-server-console/
The reason for these checks: the status in the web interface comes from a heartbeat the Scheduler records in the Devolutions Server database every minute, not from the Windows service, and it is reported offline, shown as Down, once none has arrived for two minutes. If the Offline status you mean is shown in the Devolutions Server Console instead, please tell us which column shows it and what it says, since the Console reads the Windows service itself rather than the heartbeat.
Once we have the package and the two screenshots, we will go through them and come back to you.
Best regards,
Michel
