Why is Symantec Scan Engine/Symantec Protection Engine throwing Decomposer Error 24 and/or Generic Error 24, and what are some steps that can be taken to troubleshoot this error?
Generic Error 24 is Unexpected Exception Caught, and Decomposer 24 Error is for Tempfile Access Failed. Both Errors are closely related. There are multiple reasons why these errors can be thrown, although typically these errors are thrown as a result of low disk space on the Symantec Scan Engine/Symantec Protection Engine Server ("Scan Engine"). Specifically when a Symantec Scan Engine thread is writing a file to the Scan Engine temp folder, if Scan Engine runs out of disk space, this thread will error out. Which will lead to the errors mentioned above. Also note that when our thread errors out, it fails to delete the temp file it was writing to, which compounds the problem.
The solution is to make sure Symantec Scan Engine had adequate free disk space to write to Scan Engine temp folder.
Below are some steps that can be taken to try and troubleshoot this error,
1. This error can also be caused by SEP/desktop AV. Make sure that the Scan Engine temp folder is excluded from scanning. The Scan Engine temp folder path is list in the GUI, Configuration -> Resources -> Temporary directory for scanning. Additionally, if the desktop AV has a network scanning feature, please make sure this feature is disabled. As it can cause these errors to be thrown by Scan Engine.
2. Confirm that no other processes/applications, other then Symantec Scan Engine, are accessing the Scan Engine temp folder. A tool like file monitor can be used to confirm this.
3. The best way to confirm if the Decomposer/Generic 24 errors are caused by low disk space would be to monitor the box while the issue is occurring. While the issue is occurring, attempt to monitor the how much free disk space the Symantec Scan Engine server has. Additionally, check inside of the temp folder of Scan Engine. If these errors are produced by low disk space, there should be a build of old temp files that Scan Engine failed to delete (for reasons mentioned above). Note, if Scan Engine is restarted these old temp files will be deleted by Scan Engine. So the temp folder needs to be checked before Scan Engine is shut down.
4. If this does not help, please contact Support to further troubleshoot the issue.