This article explains what can be done if a job fails in Imaging Engine with the error message "SL/DL IO Error".
When a job is sent to Imaging Engine, it fails to RIP and the log for the failed Imaging Engine task contains the error message "SL/DL IO Error".
When processing PDF files, the Adobe RIP kernel sometimes writes temporary files, and occasionally these files can become very large. The most likely cause of this error message is that there is no space left on the disk.
The only solution to this problem is to either free up some space on the disk that Imaging Engine runs on, or to install it on a larger disk.