What Error 9204 Means
Error 9204 reports that an Automation Studio pre-build step executed with errors. A pre-build step is a project-specific build event that runs an external action before the Automation Studio project build. It can call an external program or batch file to check, copy, move, or generate data, interact with source control, or connect the build to a CI/CD toolchain.
Automation Studio does not add pre-build or post-build actions by default. If error 9204 appears, somebody configured a build event in the project.
Where to Find the Pre-Build Step
Open the PLC-related object for the affected configuration and inspect Build Events. Review the configured pre-build action, not the post-build action: post-build actions run after the project build and are not the event identified by error 9204.
| Build event | Execution point | Relevance to error 9204 |
|---|---|---|
| Pre-build | Before the Automation Studio project build | Inspect this action |
| Post-build | After the Automation Studio project build | Not the event named by this error |
Troubleshooting the Configured Action
- Open Build Events under the PLC-related object of the affected configuration.
- Identify the configured pre-build external program, batch file, or similar action.
- Confirm that the referenced program or file exists and that the build event definition is valid.
- Execute or inspect the action and correct the condition that makes it return an error level other than
0. - Build the project again. Verification succeeds when the pre-build action completes with error level
0and error 9204 no longer appears.
The two evidence-supported failure classes are an invalid event—such as a referenced external program that does not exist—and an existing program or batch file that finishes with a nonzero error level. If the action is no longer required, have the project owner review whether the manually configured build event should remain.
FAQ
What is a pre-build step in Automation Studio?
It is a configured external action that runs before the Automation Studio project build. It can invoke a program or batch file for source-control, file-processing, data-generation, or CI/CD work.
What causes Automation Studio error 9204?
Error 9204 occurs when the pre-build event is invalid or its external action returns an error level other than 0. A missing referenced program is one documented example of an invalid event.
Where do I check the build event for error 9204?
Open the PLC-related object for the affected configuration, then inspect Build Events. Verify the pre-build action and confirm that it completes with error level 0.
