After upgrading from 6.12.1 to 7.2.0 my login screen is blank

[admin admin]

Reviewing the confluence home-dir logs this is where the issue started;

INFO [Catalina-utility-1] [com.atlassian.confluence.lifecycle] init Confluence is ready to serve
2020-01-08 01:51:18,930 ERROR [http-nio-8090-exec-10] [ContainerBase.[Standalone].[localhost].[/]] log Unhandled exception occurred whilst decorating page
-- referer: http://10.10.20.100:8090/login.action?os_destination=%2Findex.action&permissionViolation=true | url: /plugins/servlet/saml/getajaxconfig | traceId: 49835ac57c28d0a1 | userName: anonymous
java.lang.NullPointerException

When I review the server's url this is what I see;

[Zak Laughton]

Hello,

Based on the error, it appears there might be a SAML plugin that got corrupted or misconfigured during the upgrade.

It'll help the community to have a bit more information in order to troubleshoot the issue. If you can, please let us know:

• Which process did you use to upgrade Confluence:
  • Upgrading Confluence (In place, using the installer)
  • Upgrading Confluence Manually (In place, using the tar.gz or .zip file)
  • Other (please describe)
• Does your instance use a 3rd-party SAML plugin?
• Are you able to successfully run Confluence in safe mode?

Thanks!
– Zak

[admin admin]

Hi Zak,

I upgraded using the installer with a populated response.varfile

We do use a 3rd-party SAML plugin, and I am only aware of activating safe-mode from within the web gui, so I have not attempted this as yet, b/c login has been unavailable.

[Zak Laughton]

Sorry, I now realize the safe mode documentation I linked only covers the admin menu setting as you mentioned.

In order to get past this, you'll likely need to start Confluence in safe mode by following the "With add-ons disabled" steps on Start and Stop Confluence.

Once Confluence is started in safe mode, it should bypass the SAML configuration, which will let you log in as the internal Confluence admin and adjust the settings for the app.

If you're unsure of the credentials for the internal admin, you can reset them by following Restore passwords to recover admin user rights.

[admin admin]

I had not previously run across that operand, interesting.
I will give that a try next week and let you know how things go.

[Nic Brough -Adaptavist-]

You will need to read a lot more of the log than just the first line of the null pointer exception.  What is the rest of the error?

[admin admin]

Note that there isn't a proxy in front of the server.