3209526 - OAuth Token can't be retrieved via UDF in 7.50 SP20 or later

The PO can not connect to the target authorization server URL via UDF, and the message processing fails with an error similar to "HTTP Communication Error. Could not retrieve oAuth Token".

In the HTTP Client traces you see the following error:

20:58:25:178 Guest ~tp://sap.com/xi/XI/SystemCall] ~.net.connection.HttpConnection Open connection to {authorization server URL}
20:58:25:573 Guest ~tp://sap.com/xi/XI/SystemCall] ~.net.connection.HttpConnection IOException while opening the connection : 
[EXCEPTION]
java.net.SocketException: Connection reset
at java.net.SocketInputStream.read(SocketInputStream.java:210)
at java.net.SocketInputStream.read(SocketInputStream.java:141)
at iaik.security.ssl.Utils.a(SourceFile:290)
...

• SAP Process Orchestration 7.5

Process Integration, Process Orchestration 7.50, PI 7.50, PO 7.50, NetWeaver, XI, AEX, REST, Authentication, OAuth, oAuth Token , KBA , BC-XI-CON-RST , Rest Adapter , Known Error