This happens when you enter invalid SMTP Server settings under the SMTP tab.
The Security Server console does not automatically save the SMTP Server settings when switching tabs. You need to click the Save button on the bottom of each tab to save the settings you made.
If the Security Server console detects an invalid input under SMTP tab (e.g. invalid SMTP server or SMTP server unavailable or cannot connect), then you will not be able to switch tabs.
To allow switching of tabs:
- Ensure the settings are correct and valid.
- Click Save to save the settings.
For more details on setting up an SMTP server, refer to this Knowledgebase article: Setting up the SMTP Server settings.
If further assistance on the issue is needed, contact Trend Micro Technical Support.