xclock dbca PuTTY X11 proxy: Authorisation not recognised

PuTTY X11 proxy: Authorisation not recognised

Error: Can't open display: localhost:10

Error:

[dbadmin53@brvmoracle ~]$ sudo su - oracle

Last login: Wed Dec 16 09:43:51 +03 2020 on pts/0

[oracle@brvmoracle ~]$ xclock

PuTTY X11 proxy: Authorisation not recognised

Error: Can't open display: localhost:10

or 

[oracle@brvmoracle ~]$ dbca

PuTTY X11 proxy: Authorisation not recognised

Exception in thread "main" java.lang.NoClassDefFoundError: Could not initialize class sun.awt.X11.XToolkit

        at java.lang.Class.forName0(Native Method)

        at java.lang.Class.forName(Class.java:264)

        at java.awt.Toolkit$2.run(Toolkit.java:860)

        at java.awt.Toolkit$2.run(Toolkit.java:855)

        at java.security.AccessController.doPrivileged(Native Method)

        at java.awt.Toolkit.getDefaultToolkit(Toolkit.java:854)

        at com.jgoodies.looks.LookUtils.isLowResolution(LookUtils.java:484)

        at com.jgoodies.looks.LookUtils.<clinit>(LookUtils.java:249)

        at com.jgoodies.looks.plastic.PlasticLookAndFeel.<clinit>(PlasticLookAndFeel.java:135)

        at java.lang.Class.forName0(Native Method)

        at java.lang.Class.forName(Class.java:348)

        at javax.swing.SwingUtilities.loadSystemClass(SwingUtilities.java:1874)

        at javax.swing.UIManager.setLookAndFeel(UIManager.java:582)

        at oracle.install.commons.util.Application.startup(Application.java:917)

        at oracle.install.commons.flow.FlowApplication.startup(FlowApplication.java:181)

        at oracle.install.commons.flow.FlowApplication.startup(FlowApplication.java:198)

        at oracle.assistants.common.base.driver.AssistantApplication.startup(AssistantApplication.java:320)

        at oracle.assistants.dbca.driver.DBConfigurator.startup(DBConfigurator.java:342)

        at oracle.assistants.dbca.driver.DBConfigurator.main(DBConfigurator.java:386)

[oracle@brvmoracle ~]$

Reason:

Switching from 'dbadmin53' user to 'oracle' user - causing the error.

Try login with oracle user directly from putty.