FrameworkUtil now uses it internally so compiling bundles with older BREEs lead to errors like: [ERROR] /home/jenkins/agent/workspace/ecf-tycho.gerrit/TARGET_PLATFORM/2021-09/providers/bundles/org.eclipse.ecf.provider.filetransfer.httpclient45/src/org/eclipse/ecf/internal/provider/filetransfer/httpclient45/HttpClientProxyCredentialProvider.java:[195] [ERROR] String os = FrameworkUtil.getBundle(HttpClientProxyCredentialProvider.class).getBundleContext().getProperty(OSGI_OS); [ERROR] ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ [ERROR] The type java.util.Optional cannot be resolved. It is indirectly referenced from required .class files [ERROR] 1 problem (1 error)