Sage 50 Error Code 8591 is a system error that occurs when your Windows computer could not start the Pervasive PSQL Workgroup Engine. The main cause of this problem is when the W3dbsmgr.exe process is running on your Windows computer. You can call the Sage customer support number and consult an expert to know the best way to end this process so that you can continue using Sage 50. The Sage helpline is active 24 hours a day so that you can quickly resolve any error and get back to your accounting tasks.