Enabling Changes API fails with an error:
Akci se nepodařilo provést: Failed to query single object for SQL 'select create_or_drop_changes_triggers(true)'
Cause and Solution
Both enabling and disabling change tracking creates and drops database triggers, which cannot be done while logged-in users are simultaneously working with the database. Log out all users and repeat the action.
The server status shows how many users are logged in:
GET https://{server}:5434/status.json
You're interested in the fields loggedUser, loggedUserRO, loggedUserRW and sessions. The current state of change tracking is then returned by:
GET /c/{firma}/changes/status.xml
💡 Users can also be logged out via the API — the procedure is described in the article Logging Out Users in the REST API.