Java Standard: successfully deploy but no instances: The server encountered an error and could not complete your request.

[Jonathan Tinsman]

I recently had to do an update to an older Java Spring Boot application and initially ran into a problem connecting to firebase. I had tried several different configurations, all of which deployed to GAE successfully until I realized that I had to update my firebase-admin sdk to 3.x. Once doing that, locally it worked fine; however, when I deploy to GAE it never starts any instances.

I deploy using the Maven command from the GAE command-line console as I always do and it successfully deploys, but when I click the link to go to `/` I get a 500 and "The server encountered an error and could not complete your request."

My appengine-web.xml

<appengine-web-app xmlns="http://appengine.google.com/ns/1.0">

  <application>XXXappnameXXX</application>

  <version>1</version>

  <threadsafe>true</threadsafe>

  <runtime>java8</runtime>

  <manual-scaling>

    <instances>1</instances>

  </manual-scaling>

</appengine-web-app>

and using the maven appengine-maven-plugin v1.3.1 with spring-boot-starter-parent v1.5.7.RELEASE

[George (Cloud Platform Support)]

Hello Jonathan, 

Have you had a look at your logs? In Cloud Console, you should navigate to logging and examine logs for any relevant message. To narrow down your investigation, you should select logging level as "error", or "debug". As a first step, if you notice session support is not enabled in appengine-web.xml, try editing appengine-web.xml, and adding line: <sessions-enabled>true</sessions-enabled>. 

Does situation come back to normal if you revert firebase-admin sdk to a version prior to 3.x?

You are encouraged to open a private issue with similar contents in Public Issue Tracker, where private details, such as project names, can be exchanged safely, away from public scrutiny, if you mark the issue as private. Public forums such as Groups are not suitable in this respect.  

[Jonathan Tinsman]

George,

Thank you for the reply. I hadn't noticed that the logs were showing the same message about not starting correctly. Looking back in the logs it showed a compile error around the upgraded library saying method not found. I had to do a `mvn clean install` in order for it to pull down the new library. I would have thought the build would have failed with an incorrect version of the library but I guess I missed a newbie mistake. Thank you.

Jonathan.

[George (Cloud Platform Support)]

Glad to read you have troubleshot your issue successfully. You are welcome opening separate issues in the Public Issue Tracker, if you are faced with other Cloud Platform related problems.