You cannot change the posting method to SmartPosting if SmartPosting is not running
Sage 50 is refusing the switch because the SmartPosting background service is not active on your system.
Sage 50 is telling you, in a roundabout way, that a background component it calls SmartPosting is not currently running, so the program will not let you select it as a posting method. The message reads:
You cannot change the posting method to SmartPosting if SmartPosting is not running.
SmartPosting is an option that lets Sage 50 post journal entries in the background rather than immediately when you save them. Because the work is handed off to a separate process, that process has to be alive before Sage 50 will accept the setting change. The message is not about your data being wrong. It is about a service that should be running and is not.
Why the service may not be running
The SmartPosting component normally starts with Sage 50. It can fail to start after a Windows update, an interrupted Sage 50 update, a permissions problem on the machine hosting the company data, or security software blocking the background process. On a multi-user setup, the service runs on the computer that hosts the data, so a problem on the server shows up on every workstation.
A restart of the computer hosting the company data is often enough to bring it back. If the message returns after restarting, the installation itself may be damaged.
What to check first
Close Sage 50 completely and restart the computer that holds your company data, not just your workstation. Open Sage 50 again and try changing the posting method once more. If you are on a network, confirm other users are out of the file while you change the setting.
If it still refuses, repairing or reinstalling Sage 50 on the affected machine is the next safe step. Have your Sage 50 installation media or download and your serial number handy before you start, and take a fresh backup of your company data first.
When the posting method matters more than the setting
Some readers hit this message because they want to move off SmartPosting entirely, or because a conversion to another product depends on how entries are posted. If your real goal is getting your Sage 50 data into QuickBooks, the posting method inside Sage 50 does not have to be solved first. Our Sage 50 to QuickBooks conversion service works from your existing data regardless of this setting, and for the Canadian edition see our Simply Accounting to QuickBooks conversion.
If the file itself is the problem
Occasionally this message appears alongside other symptoms: slow opening, errors on backup, or postings that never appear in the ledger. That pattern suggests the company database is damaged rather than the service simply being stopped. Our engineers handle that situation directly through our Sage 50 database repair service.
If a reinstall does not clear the message, or if you are seeing other errors in the same file, send us the file for a free evaluation. We will tell you what is wrong and what the fix involves before you commit to anything.