error while upgrade JDK from 8 to 14
Asked by hellojinjie:

I upgraded confluence from 6.13.0 to 7.6.2 followed this page <https://confluence.atlassian.com/doc/upgrading-confluence-manually-255363437.html>

It is all OK to start confluence using the original JDK 8.

After finished the upgrade, I changed the JDK from 8 to 14, confluence can NOT start, logs/catalina.out has following error message:

```
WARNING: An illegal reflective access operation has occurred
WARNING: Illegal reflective access by org.apache.felix.framework.ext.ClassPathExtenderFactory$DefaultClassLoaderExtender (file:/home/tzc/atlassian/atlassian-confluence-7.6.2/confluence/WEB-INF/lib/org.apache.felix.framework-5.6.12.jar) to method java.net.URLClassLoader.addURL(java.net.URL)
WARNING: Please consider reporting this to the maintainers of org.apache.felix.framework.ext.ClassPathExtenderFactory$DefaultClassLoaderExtender
WARNING: Use --illegal-access=warn to enable warnings of further illegal reflective access operations
WARNING: All illegal access operations will be denied in a future release
04-Aug-2020 11:04:10.598 SEVERE [Catalina-utility-1] org.apache.catalina.core.StandardContext.startInternal One or more Filters failed to start. Full details will be found in the appropriate container log file
04-Aug-2020 11:04:10.598 SEVERE [Catalina-utility-1] org.apache.catalina.core.StandardContext.startInternal Context [] startup failed due to previous errors
WARNING: Cannot update an inactive framework.
```


Answers:
author: Shannon S
body: Hello [@hellojinjie](/t5/user/viewprofilepage/user-id/1019731),

Thank you for bringing this up to us. The issue here is that JDK 14 is not supported by Confluence. The article you followed, [Upgrading Confluence Manually](https://confluence.atlassian.com/doc/upgrading-confluence-manually-255363437.html), provides a link to our Supported Platforms page for your review under the following:
> **Have our supported platforms changed?**
>
> Check the [Supported Platforms](https://confluence.atlassian.com/doc/supported-platforms-207488198.html) page for the version of Confluence you are upgrading to. This will give you info on supported operating systems, databases and browsers.

According to this, the following JAVA versions are supported:
> **Oracle JRE / JDK**
>
> ![(tick)](https://confluence.atlassian.com/s/en_GB/7901/af536c7c6dffcc1d697b914b797aa7f2f306b4f8/_/images/icons/emoticons/check.svg) Java 1.8
>
> ![(tick)](https://confluence.atlassian.com/s/en_GB/7901/af536c7c6dffcc1d697b914b797aa7f2f306b4f8/_/images/icons/emoticons/check.svg) Java 11
>
> **AdoptOpenJDK**
>
> ![(tick)](https://confluence.atlassian.com/s/en_GB/7901/af536c7c6dffcc1d697b914b797aa7f2f306b4f8/_/images/icons/emoticons/check.svg) Java 8 (HotSpot)
>
> ![(tick)](https://confluence.atlassian.com/s/en_GB/7901/af536c7c6dffcc1d697b914b797aa7f2f306b4f8/_/images/icons/emoticons/check.svg) Java 11 (HotSpot)

You will need to roll back to a [supported JAVA version](https://confluence.atlassian.com/doc/change-the-java-vendor-or-version-confluence-uses-962342397.html) in order to support Confluence. Could you please give that a try, and let me know if you continue to have the issue?

Take care,

Shannon