You encounter this error message intermittently when printing from an integration:
BarTender 2016 and later.
BarTender's Minimum Specifications
This issue occurs inconsistently but usually happens more often if you are experiencing a high load of print jobs. This error message is likely caused by a lack of system resources. When too many print jobs are created at once, it's possible to overwhelm a computer that doesn't have the minimum resources to run that many print jobs simultaneously.
Compare your computer's technical specifications to BarTender's minimum specifications. If your computer doesn't match the minimum specifications, an upgrade to the lacking resource can help. If you have your integrations deployed on a Virtual Machine (VM), you can devote additional resources to the VM to resolve the issue.
Maximum Number of Print Engines Exceeded
If your computer meets BarTender's minimum technical specifications, your integration(s) may exceed the number of created print engines that your computer can handle.
A Print Engine is another term for BarTender Designer running as a service, and one is created each time a print job is queued by your integration. They facilitate the automated printing of your labels. Print engines are automatic, and you do not need to open or close them yourself, as the Print Scheduler service handles it for you.
You can have a maximum number of print engines equal to the number of cores in your CPU times two. Each print engine can handle five documents at a time. For example, if you have two processors with two cores each, you can run eight integrations simultaneously.
If you investigate and discover that you exceed your maximum number of allowed print engines, consider increasing your computer's available resources or redeploying some of your integrations on another computer to reduce the load.