Issue

The administrative monitor tool is displaying the following warning message: ‘There are some masters with an incompatible version of [plugin] installed’.
For instance, it could be ‘There are some masters with an incompatible version of [saml] installed’.

Environment

• CloudBees Core on modern cloud platforms - Operations Center
• CloudBees Core on traditional platforms - Operations Center
• CloudBees Jenkins Enterprise - Operations Center
• CloudBees Jenkins Platform - Operations Center
• Operations Center Single Sign-On Plugin

Resolution

This administrative monitor detects that
* you have a master configured to use the Operation Center security realms
* this master does not have the necessary plugin to operate the security realms by itself in case the Operation Center goes offline

To fix the issue, you simply need to install the plugin which is providing the security realm, on the masters that do not have it installed or have a different version from the one already installed in the OC

For instance, in the case of the message: ‘There are some masters with an incompatible version of [saml] installed’, you need to install the SAML plugin on the masters missing it or using a version different from the one installed in the Operation Center.