A: Some common solutions to solve authorization errors in SCSM are listed here. The first thing to try is add your workflow account to the Service Manager Administrator role by launching the System Center Service Manager Console and navigating to Administration, Security, User Roles. Select Administrators then click the Properties action. Scroll down to the bottom of the properties or click Users in the navigation and add the workflow account to the role using the Add button. Click OK.
The above cures most workflow problems. If you're seeing errors related to access to Event Logs, and more specifically the Security event log, the solution I found was to use the registry editor on the Service Manager management server to give your workflow account Full Control to the registry keys HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\eventlog\Security and HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\eventlog.