APBackup allows you to run backup tasks using both the built-in Zip64 archiver and the majority of external archivers. To configure an external archiver for use with APBackup, you need to create/edit an external archiver configuration file (*.EMC). The APBackup distribution package contains configuration files for the most popular tools: WinRar, WinZip, Arj, 7-Zip, etc. However, you can add a custom configuration file for any other archiver. The process is described in detail in the program documentation (where WinRar is used as an example).
When a task is executed using an external archiver, APBackup creates a command line to start it using the information from the corresponding configuration file, creates a process for executing this command line and waits for the process to end. In this case, an archiving task is considered completed if the return code of the created process is 0 and the program finds a newly-created volume after the external archiver has finished working. If the external archiver returns a code different from 0, it means that the task has been completed with an error. Unfortunately, APBackup cannot identify what’s causing the error, as it is related to a different process it has no access to. So what can you do to find the source of the problem?
