If you can't get to any of the HTTPS pages this is probably it.
Here are the steps to fix:
1. Open iKeyMan - C:\IBM\HTTPServer\bin\ikeyman.bat
2. Click the open folder and retrieve file: C:\IBM\HTTPServer\SSLKeys\sslkeys.kdb - Enter the password e.g. "Pass0wrd".
3. Click "Delete".
4. Click New Self-Signed...
5. Type in label "CLIENT_INITIALS".
6. Save/Close it.
7. Open your Windows Services and restart the IBM HTTP Server.
8. Restart your toolkit (if started already).
9. Test https://localhost