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Class changes to @baseclass on performing a Save or Save-As



User clicks the Save As button on the property while saving the rules. However, the rule gets saved in @baseclass. 

Error Messages

657(ctionWrapper._baseclass.Action) ERROR - Activity pzPostRuleFormValues failed to execute, RH_1, page class is null
950 (ngineinterface.service.HttpAPI) WARN : Error adopting XML from post data : InvalidStream, StorageStream) sax parse error: Content is not allowed in prolog.
at ~[prprivate-data.jar:?]
at ~[prprivate-data.jar:?]
at ~[prprivate-data.jar:?]
at com.pega.pegarules.session.internal.engineinterface.service.HttpAPI.mapInputData( ~[prprivate-session.jar:?]
at com.pega.pegarules.session.external.engineinterface.service.EngineAPI.activityExecutionProlog( ~[prenginext.jar:?]
at com.pega.pegarules.session.external.engineinterface.service.EngineAPI.processRequestInner( ~[prenginext.jar:?]
Caused by: org.xml.sax.SAXParseException: Content is not allowed in prolog.
at []
at ~[]

Steps to Reproduce

  1. Open an existing rule
  2. Click the Save As button. However, @baseclass displays on the opened rule form

Root Cause

A defect or configuration issue in the operating environment. Tomcat 9.0.31 with Non-blocking Input/Output (NIO) protocol is used which causes the failure of the Post requests.


Perform the following local-change:
Use the NIO2 protocol in the Apache Tomcat 9.0.31 configuration as below, instead of NIO:

<Connector port="8080" protocol="org.apache.coyote.http11.Http11Nio2Protocol"connectionTimeout="20000" redirectPort="8443"/>

NIO and NIO2 are same in Network and Sockets. NIO2 is advanced in terms of file system operations.

Alternatively, update to Tomcat 9.0.32 to resolve the issue.


Published August 13, 2020 - Updated December 2, 2021

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