3497850 - 'Trust Agents' is failed with an error 'Access Denied'

Clicking on 'Trust Agents' is failed with an error 'Access Denied'.
From SMDSystem.*.log, below error was found:

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Error Could not create transientInitialContext with authentication: will now try again without authentication:

[EXCEPTION]
javax.naming.NamingException: Exception during getInitialContext operation. Cannot establish connection to the remote server. [Root exception is com.sap.engine.services.security.exceptions.BaseLoginException: Access Denied.]
<...>
Caused by: com.sap.engine.services.security.exceptions.BaseLoginException: Access Denied.
<...>
Caused by: java.lang.SecurityException: Internal server error. An error log with ID [<ID>] is created. For more information contact your system administrator.
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Or/And

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Error      Failed to connect to SMD server - CN=Agent Authentication - CA Certificate,OU=SAP AGS,O=SAP,C=DE
Error Connecting to SMD server ms://<Solution Manager Java FQDN>:<MsgServer HTTP port number>/P4 failed. Exception cause value: -1

[EXCEPTION]
com.sap.engine.services.security.exceptions.BaseLoginException: Access Denied.
<...>
Caused by: java.lang.SecurityException: Internal server error. An error log with ID [<ID>] is created. For more information contact your system administrator.
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Solution Manager 7.2

 Diagnostics Agent

Trust Agent, certFromKeyStore, X509Certificate, a null object loaded from local variable, No logon policy was applied, getSubjectDN, self signed certificate , KBA , SV-SMG-DIA-SRV-AGT , Agent Framework , Problem