2952313 - REST Adapter with Basic Authentication fails after update/upgrade to Netweaver 7.50 SP17 or higher

• You have a REST Adapter Receiver or Poller channel which is configured with Basic Authentication. After a system upgrade/update to Netweaver 7.50 SP17 or higher, all the messages processed in this channel started to fail with HTTP 401 or similar HTTP error.
• When reproducing the error and capturing an XPI Inspector trace, in the HTTP Client traces, you can see that no Authorization Basic header is set in the request header.
• There can also be an issue where you see that the message gets processed in PI but the server sees two entries one is 401 and then a 200 status message. An XPI inspector trace with HTTP client full dump shows two request calls going to the server. 

SAP NetWeaver 7.5

Preemptive, HTTP 401, HTTP 403, Rest, Basic, Receiver, Poller, Poll, Sender, Authentication, Security, Upgrade, Update, Fail, Not, Working, Header, Rquest, Process Orchestration 7.5, PI 7.5, PO 7.5, XI, AEX , KBA , BC-XI-CON-RST , Rest Adapter , Problem