The secure sockets layer (SSL) certificate sent by the server was invalid and this item will not be crawled

Error we faced today in a next production environment, we used a self signed certificate and we receive this error when we tried to crawl the app web:

The secure sockets layer (SSL) certificate sent by the server was invalid and this item will not be crawled

Solution:

 Go to Central Administration > Application Management > Manage services on server >  Sharepoint Server Search and set it to ignore SSL warnings. Repeat full crawl of your content source again.

Or in powershell:

$searchService = Get-SPEnterpriseSearchService

if($searchService.IgnoreSSLWarnings -eq $false)

{

    Write-Host "3. Setting Ignore SSL Warnings to true..." -NoNewline

$searchService.IgnoreSSLWarnings = $true

    Write-Host "OK"

}

Hope it helps