While enabling the CSSA (Cloud Search Service Application) I came across this error during first full crawl after successfully completing the on-boarding steps outlined at https://blogs.msdn.microsoft.com/spses/2015/09/15/cloud-hybrid-search-service-application/ with PowerShell scripts.    The Azure plugin was unable to crawl on-premise content.   Root cause was proxy server configuration, which needs to be consistent across three places.  Hope this helps!

Central Admin

An unexpected error occurred in the Azure plugin. This item will be retried in the next incremental crawl. ( AzureException AzurePlugin was not able to get Tenant Info from configuration server; SearchID = B056F137-1C77-4792-B402-256B615DBE82 )

Verbose ULS

Get-SPLogLevel |? {$_.Area -like "SharePoint Server Search"} | Set-SPLogLevel -TraceSeverity VerboseEx
New-SPLogFile

ULS Log

By running PowerShell commands “Set-SPLogLevel” and “New-SPLogFile” I was able to get verbose URL for the CSSA crawl process.   Here are the entries showing inability to communicate over the proxy server to the Internet.

12/08/2016 15:36:31.55  mssearch.exe (0x195C) 0x0B18  SharePoint Server Search             Crawler:Azure Plugin                amn0f   High       AzureServiceProxy::GetCerts caught AggregateException: The ServicePointManager does not support proxies with the myproxy scheme.  

12/08/2016 15:36:31.55  mssearch.exe (0x195C) 0x0B18  SharePoint Server Search             Crawler:Azure Plugin                amn0g  High       AzureServiceProxy::GetCerts: Failed to get encryption certificates from cert server https://tenant.sharepoint.com for realm 67d7b889-884d-4c2a-a8d8-3ff81f37b497, documents will be send unencrypted (if unecrypted submit is allowed) 

12/08/2016 15:36:31.55  mssearch.exe (0x195C) 0x0B18  SharePoint Server Search             Crawler:Azure Plugin                amn0h  High       AzureServiceProxy::GetAzureTenantInfo caught AggregateException: The ServicePointManager does not support proxies with the myproxy scheme., unable to get EndpointAddress, submit is blocked               

12/08/2016 15:36:31.55  mssearch.exe (0x195C) 0x0B18  SharePoint Server Search             Crawler:Azure Plugin                amn0i    High       AzureServiceProxy caught Exception: *** Microsoft.Office.Server.Search.AzureSearchService.AzureException: AzurePlugin was not able to get Tenant Info from configuration server     at Microsoft.Office.Server.Search.AzureSearchService.AzureServiceProxy.GetAzureTenantInfo(String portalURL, String realm, String& returnPropertyValue, String propertyName)     at Microsoft.Office.Server.Search.AzureSearchService.AzureServiceProxy.SubmitDocuments(String azureServiceLocation, String authRealm, String SPOServiceTenantID, String SearchContentService_ContentFarmId, String portalURL, String testId, String encryptionCert, Boolean allowUnencryptedSubmit, sSubmitDocument[] documents, sDocumentResult[]& results, sAzureRequestInfo& RequestInfo) ***   

Resolution

Proxy server settings need to be confirmed in three places.   The crawler was attempting to use “myproxy:8080” DNS names when it actually needs URL format “http://myproxy:8080”   

1)  Internet Explorer

Tools > Options > Connections > LAN Settings

Provide either PAC URL (proxy auto config) or proxy server DNS name.

2)  Command Line

NETSH WINHTTP SHOW PROXY

NETSH WINHTTP SET PROXY PROXY-SERVER=”myproxy:8080” BYPASS-LIST=”*.company.com;<local>”

3)  Dot Net Global [machine.config]

Run notepad

Open “C:\Windows\Microsoft.NET\Framework64\v4.0.30319\config\machine.config”

Add following XML code

<system.net>
<defaultProxy>
<proxy usesystemdefault=”false” proxyaddress=”http://myproxy:8080” bypassonlocal=”true” />
</defaultProxy>
</system.net>

Notes

• Completed the “Hybrid Onedrive” click once application to create “ACS” and “SPO” service application proxies before Hybrid Search CSSA onboarding.   https://configure.office.com/

References

• https://support.office.com/en-us/article/SharePoint-hybrid-sites-and-search-5ff7e56a-7af2-4511-adec-1e043afe244e
• https://blogs.msdn.microsoft.com/spses/2015/09/15/cloud-hybrid-search-service-application
• https://blogs.msdn.microsoft.com/spses/2015/05/20/the-all-new-cloud-search-service-application-coming-to-sharepoint-2013-and-sharepoint-2016/
• https://github.com/spjeff/office365/tree/master/office365-hybrid-search-cssa
• https://thesharepointfarm.com/2016/12/cloud-search-service-application-crawl-performance