GoldenGate Trail Purge Task Fails with “OGG-12111: JSON element ‘/csn’ does not match any schemas”

Since the beginning of the year, I had the opportunity to upgrade many GoldenGate setups to 26ai. On two of them, I was facing an issue regarding purge tasks that I could not solve. Since it took quite some time to finally find a solution, I figured it was worth documenting.

The client had two GoldenGate 26ai installations running on the same server.

• One extracting data from DB2, with GoldenGate for DB2/zOS.
• One replicating into an Oracle 19c database, reading from the same trail files.

Both setups were using the initial release of GoldenGate 26ai.

On both, I tried to set up trail purge tasks from the Administration Service web UI, and both GoldenGate trail purge failed with the same error.

Purge task creation from the web UI

To add a purge task, go to the Administration Service web UI, and on the left navigation panel, click on Tasks > Purge Trail.

From there, create a new task. You will be asked to provide a task name, one or multiple trail paths, retention rules, and whether to use checkpoints when purging trail files.

In my case, right after the creation, the purge task was failing with the OGG-12111 error. This happened no matter how I configured the task. The task was correctly configured, but it would fail every time it was scheduled to run

OGG-12111 in the web UI

The full error displayed was the following:

JSON element '/csn' does not match any schemas
Code: OGG-12111
Cause: The JSON item does not validate against the provided JSON schema.
Action: Correct the JSON so that it conforms to the JSON schema.

I first thought that it was a configuration issue on my side, but there is no such csn field when configuring the task. I quickly realized that if something was wrong, it was internal to GoldenGate. And unfortunately, all trail files were affected in this setup, so there was no working example to investigate further. On all other setups that I worked on, I never faced the OGG-12111 error.

Analysis of adminsrvr.log

Digging into the Administration Service log, I found the real error underneath:

2026-04-20T14:18:41.377+0200 ERROR| ERROR   OGG-01072  Oracle GoldenGate Administration Service for Oracle:  NUMCNV_getUnsignedNumFromStr: Buffer overflow, needed: 21, allocated: 20. (Purge)

OGG-01072 is a buffer overflow in an internal GoldenGate method. It looked like a corrupted value gets embedded into the purge task JSON, and the JSON fails schema validation. And in the end, you get the OGG-12111 error in the web UI.

OGG-12111 was just the symptom, while OGG-01072 was the actual bug.

Unfortunately, I couldn’t find any MOS bug filed for this. However, by trial and error, I discovered that the fix appears to have been introduced silently in a later patch, maybe through another bug resolution (that I could not identify).

How to solve OGG-12111 errors in GoldenGate 26ai ?

The only solution I found was patching GoldenGate to 23.26.2.0.1. I didn’t test the intermediate patch levels between 23.26.1.0.0 and 23.26.2.0.1, so I can’t say exactly which patch introduced the fix, but upgrading to 23.26.2.0.1 resolved the issue.

After patching, I went back to the Purge Trail section of the web UI, and the existing purge tasks were already working. I did not even have to recreate them.

So if you face this bug and your GoldenGate trail purge fails, don’t spend time reviewing the purge task parameters. Your tasks are most probably fine. The bug is inside the Administration Service’s numeric conversion method, and patching is the only way out.