Support Article

Unable to view a decision tree in Pega 7.2 after upgrade



After upgrading from PRPC 6.2 SP2 to Pega 7.2, several decision tree rules are not opening in the Designer Studio. Instead of opening a new tab that shows the ruleform, the tab appears blank and never finishes loading. The tab's title is displayed as "Opening..." instead of the decision tree rule's name.

Error Messages

Caused by: Async IO operation failed (1), reason: RC: 32 There is no process to read data written to a pipe.

Steps to Reproduce

  1. Upgrade from PRPC 6.2 SP2 to Pega 7.2.
  2. Attempt to open an affected decision tree rule in the Designer Studio.

Root Cause

A defect in Pegasystems’ code or rules.


Perform the following local-change:
  1. Do a Private Edit of the pzIfAllowedValuesNonBlank When rule (RuleSet is Pega-ProcessArchitect:07-10-15, class is @baseclass).
  2. Change the Logic string from "A OR B" to "NOT (A OR B)".
  3. Click the "Save" button.
Now user is able to open, edit and save the affected decision tree rules and make any updates and corrections that is required.

After updating and correcting the affected decision tree rules, one should discard the Private Edit of the pzIfAllowedValuesNonBlank When rule.


Published November 22, 2016 - Updated November 30, 2016

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