Server Error in '/' Application
The resource cannot be found.
Description: HTTP 404, The resource you are looking for(or one of the dependencies) Could have removed, had its name changed, or is temporarily unavailable.Please review the following URL and make sure that it is spelled correctly.
Request URL: /enterprisevault/search/shell.aspx

In client Trace log, below entries are seen:
28/01/2019 12:59:59.536[7088][M]: HaveConnection::ExecuteTest – Connection test to: xxxxx/EnterpriseVault/clienttest.gif failed
28/01/2019 12:59:59.538[7088][M]: HaveConnection::ExecuteTest (80184779) – Ending connection
28/01/2019 12:59:59.538[7088][L]: ~HaveConnection::ExecuteTest
28/01/2019 12:59:59.538[7088][H]: Could not contact the EV web server (https://serveralias/EnterpriseVault) directly
28/01/2019 12:59:59.539[7088][L]: DesktopCommonConfig::GetSetting: 0x0
28/01/2019 12:59:59.539[7088][M]: Desktop Setting: RPCOVERHTTPPROXYURL
28/01/2019 12:59:59.540[7088][M]: Value: https://serveralias/EnterpriseVault
28/01/2019 12:59:59.540[7088][L]: ~DesktopCommonConfig::GetSetting: 0x0
28/01/2019 12:59:59.541[7088][H]: Trying the Alternative Web Application URL (https://serveralias/EnterpriseVault)
And when launching search vault in outlook it shows search URL getting routed to Exchange server:
Launching EV web application in Outlook: https://Exchangeserver.com/enterprisevault/search/shell.aspx?server=exchnagealias&mbx=SMTP:user@domain.com.tr&vaultid=1234567374F6230479736AB5CB8A5E2A81110000evserver&NAV0
1. Open Internet Explorer and navigate to Internet options >Advanced.
2. Scroll down to the Security section and Uncheck check box for following settings:

3. Restart Outlook.