Linux client upgrade from NetBackup 8.0 to higher version fails "WARNING: Previously reported errors getting security status prevent setting up secure communication."

Problem

Linux client upgrade from NetBackup 8.0 to higher version fails "WARNING: Previously reported errors getting security status prevent setting up secure communication."

Error Message

During client update:
WARNING: Previously reported errors getting security status prevent setting up secure communication.
Do you wish to proceed with installation even though NetBackup may not operate? [y,n]
 

Manual certificate generation fails on client:
nbcertcmd -getCAcertificate
Status 42

Troubleshooting on client by setting up verbose logging:
In /usr/openv/netbackup/bp.conf
          VERBOSE=5                 
     ENABLE_NBCURL_VERBOSE=1  

------------------------------------------------------------------

NOTE:  proxy  HTTP error in client nbcert log 

Location: /usr/openv/netbackup/logs/nbcert

<2> NBClientCURL::resetCurlResolver: Hostname resolution set to [<Primary_Server>:1556:1.2.3.4].
<2> curl_debug_logger(): == Info: Added <Primary_Server>:1556:1.2.3.4 to DNS cache
<2> curl_debug_logger(): == Info: Uses proxy env variable HTTPS_PROXY == '<proxy_server>:8080'
<2> nbclnt_curl_prefnet::operator vnet_socket_t(): Returning this->m_fd
<2> curl_debug_logger(): == Info: Trying 1.2.3.10:8080...
<2> nbclnt_curl_prefnet::operator vnet_socket_t(): Returning this->m_fd
<2> curl_debug_logger(): == Info: Connected to <proxy_server> (1.2.3.10) port 8080 (#0)
<2> curl_debug_logger(): == Info: allocate connect buffer!
<2> curl_debug_logger(): == Info: Establish HTTP proxy tunnel to <Primary_Server>:1556
<2> curl_debug_logger(): => Send header, 0000000100 bytes (0x00000064) 0000: CONNECT <Primary_Server>:1556 HTTP/1.1
<2> curl_debug_logger(): => Send header, 0000000100 bytes (0x00000064) 002b: Host: <Primary_Server>:1556
<2> curl_debug_logger(): => Send header, 0000000100 bytes (0x00000064) 004b: Proxy-Connection: ***
<2> curl_debug_logger(): => Send header, 0000000100 bytes (0x00000064) 0062:
<2> curl_debug_logger(): <= Recv header, 0000000050 bytes (0x00000032) 0000: HTTP/1.1 502 Failure connecting to target master
<2> curl_debug_logger(): <= Recv header, 0000000022 bytes (0x00000016) 0000: X-Connection-ID: ***
<2> curl_debug_logger(): <= Recv header, 0000000022 bytes (0x00000016) 0000: X-Target-Master: ***
<2> curl_debug_logger(): <= Recv header, 0000000025 bytes (0x00000019) 0000: X-Target-Master-ID: ***
<2> curl_debug_logger(): <= Recv header, 0000000002 bytes (0x00000002) 0000:
<2> curl_debug_logger(): == Info: Received HTTP code 502 from proxy after CONNECT
<2> curl_debug_logger(): == Info: CONNECT phase completed!
<2> curl_debug_logger(): == Info: Closing connection 0
<16> NBClientCURL::performCurlOperation: Failed to perform operation: Failure when receiving data from the peer
<2> mapCurlError: Translating CURL status [56] to NetBackup status [42]
<2> NBClientCURL::performCurlOperation: Fetched httpcode = 502
<2> NBClientCURL::decideNextConnectRetryAction: nbErrorCode = 42 | curl error = 56 | m_httpCode = 502 | tunnelUsed = 0
<16> nbcert_curl_ping: Failed to perform ping , with error code: 42 for URI path: netbackup/security/ping

Cause

The Linux Operating System environment variables on the NetBackup client were defining proxy settings for http_proxy and https_proxy. 
The proxy settings replace the NetBackup primary server as the CA (Certificate Authority) for the certificate exchange.

Example Output of the environment variables:
$ env | grep -i http
http_proxy=http://1.2.3.10:8080
https_proxy=https://1.2.3.10:8080
 

Solution

NetBackup application on client needs to be excluded from client environment proxy connection.
Consult with the operating system administrator to disable the http proxy.
Unset the environment variables to allow NetBackup to communicate correctly.
     $ unset http_proxy
     $ unset https_proxy