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Support Article

Error while opening a class instance.



User has migrated from Pega 7.2.2 to Pega 7.3 with Pega Customer Service 7.22, after that when a class definition is opened from application explorer the following error occurs.

Error Messages

Save Failed: Trying to save an invalid page: The page contains an undefined property: NewFWWorkTypeClass.pyRecordHistorySnapshots Validation failed: Errors Detected. Trying to save an invalid page: page is not valid.

Steps to Reproduce

  1. Go to Designer studio.
  2. Open the App Explorer.
  3. Right click on the Class and select the Definition option.

Root Cause

The error is already stored in the class.

Further investigation suggests that the original error was stored in the classes during the use of the application accelerator. Notice the mention of NewFWWorkTypeClass in the error message. That happens to be the name of the step page used in activity Rule-Obj-Class.pzCopyFrameworkWorkType in step 11 where it does the page-new with the comment saying "New page for the FW work type".


  1. Private edit the @baseclass.BulkValidateSave.
  2. Add a Page-Clear-Messages step after the Obj-Open-By-Handle method call (After 2nd step).
  3. Save the activity.
  4. Run Revalidate and Save utility on effected classes.

Published October 13, 2017 - Updated December 2, 2021

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