If you just installed the Azure Information Protection on-premises scanner and you are trying to start your first Content Scan Job, you might get that the button “Scan now” is greyed out.
Before attempting to troubleshoot, check that you selected the job below. If you did, try restarting the service “Azure Information Protection Scanner” on the SQL server and refreshing the Azure Content scan job page.
If you still cannot start the scan, try executing the following command on the SQL server, and insert the credentials of the service account:
$scanner_account_creds= Get-Credential Start-AIPScannerDiagnostics -onbehalf $scanner_account_creds -Verbose -VerboseErrorCount 50
For further information refer to the following articles:
Troubleshooting your unified labeling on-premises scanner deployment