# Unable to install Jenkins Plugin after upgrading the jenkins version to 2.455

**URL:** <https://community.jenkins.io/t/unable-to-install-jenkins-plugin-after-upgrading-the-jenkins-version-to-2-455/14698>\
**Category:** Using Jenkins\
**Tags:** question\
**Created:** [April 30, 2024, 1:03pm UTC](https://community.jenkins.io/t/unable-to-install-jenkins-plugin-after-upgrading-the-jenkins-version-to-2-455/14698 "2024-04-30T13:03:06Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![sachinTen](https://avatars.discourse-cdn.com/v4/letter/s/5daacb/32.png) [@sachinTen](https://community.jenkins.io/u/sachinTen)\
**Post date:** [April 30, 2024, 1:03pm UTC](https://community.jenkins.io/t/unable-to-install-jenkins-plugin-after-upgrading-the-jenkins-version-to-2-455/14698/1 "2024-04-30T13:03:06Z")

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Java version used → 21

Below is the error

sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target  
at java.base/sun.security.provider.certpath.SunCertPathBuilder.build(SunCertPathBuilder.java:148)  
at java.base/sun.security.provider.certpath.SunCertPathBuilder.engineBuild(SunCertPathBuilder.java:129)  
at java.base/java.security.cert.CertPathBuilder.build(CertPathBuilder.java:297)  
at java

Please help me here for some insights

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**Author:** ![poddingue](https://dub1.discourse-cdn.com/flex013/user_avatar/community.jenkins.io/poddingue/32/985_2.png) [@poddingue](https://community.jenkins.io/u/poddingue)\
**Post date:** [May 6, 2024, 8:43am UTC](https://community.jenkins.io/t/unable-to-install-jenkins-plugin-after-upgrading-the-jenkins-version-to-2-455/14698/2 "2024-05-06T08:43:41Z")

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Hello @sachinTen, and welcome to this community. 👋

The error message `sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target` typically means that the Java application is unable to establish a trusted connection to the target server because the server’s SSL/TLS certificate is not trusted.

This can happen if the server is using a self-signed certificate or a certificate issued by a Certificate Authority (CA) that is not included in Java’s default set of trusted CAs.

To resolve this issue, you need to add the server’s certificate to the Java keystore used by your Jenkins instance.

Here are the general steps:

1. Export the server’s certificate to a file. This can usually be done using a web browser or the `openssl` command-line tool.
2. Import the certificate into the Java keystore using the `keytool` command that comes with Java.

The command looks like this:  
`keytool -import -alias server-alias -keystore path/to/your/keystore.jks -file server-certificate.crt`

Restart Jenkins so it picks up the changes to the keystore.