Question: Unable to update app: Error posting to URL: <https://appengine.google.com/api/appversion/create?app_id=ethereal-zodiac-803&version=1&>
409 Conflict
Another transaction by user suganya.karthik is already in progress for app: s~ethereal-zodiac-803, version: 1. That user can undo the transaction with "appcfg rollback".

See the deployment console for more details
Unable to update app: Error posting to URL: <https://appengine.google.com/api/appversion/create?app_id=ethereal-zodiac-803&version=1&>
409 Conflict
Another transaction by user suganya.karthik is already in progress for app: s~ethereal-zodiac-803, version: 1. That user can undo the transaction with "appcfg rollback".

Answer: 
**In java, windows and eclipse:** 

Check the path for you **appengine-java-sdk**, in my case, it look like some things as. 

```
 C:\Users\camno\.p2\pool\plugins\com.google.appengine.eclipse.sdkbundle_1.9.30\appengine-java-sdk-1.9.30\bin

```

Now in the console, go to the location of sdk, by type:

```
 cd [your appengine-java-sdk path]

```

Next, you can type the command for rollback:

```
appcfg -e [your_mail_to_deploy@any.com] rollback [path to war of proyect]

```

The characteres [ ] must be no include. You can find more info about the comman arguments in <https://cloud.google.com/appengine/docs/java/tools/appcfg-arguments>
If anyone who has this issue is using Android Studio or Intellij, you can go to your Gradle/Maven tasks, click backend. and click Tasks, click google app engine, and click Rollback. instead of messing with the terminal.