Verify that the service account is not listed as inactive or externally removed in the Qlik Sense Management Console. The most common reason for this is that there is an LDAP filter in place which filters on a group where the service account is not a member of. To resolve this, tell the client's IT Dept to add the service account to the filtered group and resync the UDC (the change may take a few minutes to register so you may need to sync a few times).
Once the correct user data has been identified, update the data connections accordingly with the Qlik Service User ID and Password.
Open the Qlik Sense Management Console
Navigate to Data Connections
Locate all of the below:
Edit allmonitor_apps_REST_* connections
Enter the correct User ID and Password (as seen in Fig 1)
Save the changes.
If Qlik Sense service is running as a local administrator, you need to put the account of Local administrator within the field. (e.g. Domain\administrator)
Check the account or user id
Go to services.msc and check Qlik Sense service account
If the issue persists, test the connection with a different root admin account and ensure the password on that account is 'simple' free of special characters.
It is possible that the account used (should be the service account) may be corrupted or have too complex a password.
For additional troubleshooting and root causes, see: