We have a customer running our PB 2017 app in a Citrix Environment. They experience random crashes when generating a document for preview. By adding writes into the code to a log table on their system, we have been able to determine exactly where the crash is occurring.

We have 2 logic paths for creating the document. Both are randomly aborting in the customer's environment. We are unable to cause an abort in our development environment, and we tried replicating their production environment and were unable to reproduce there either.

The first logic path will abort during a datastore retrieve, where the setredraw option is not being used. (the datastore is later transferred to a datawindow via GetFullState/SetFullState for previewing, but the abort occurs prior to that)

The second logic path will abort after a datawindow retrieve, where the setredraw has been set to false prior to the retrieve. The abort occurs on the Setredraw(true) method after the successful retrieve.

This must mean that the abort is occurring in both paths when PowerBuilder is formatting the layout of the retrieved datawindow/datastore report data. This document is a composite dataobject with a nested header report and multiple nested reports in the detail band, with autosizing turned on for the bands and the nested reports.

The termination is not dependent on the data, as the log shows the same user attempting to display the same document 3 minutes apart, using the same logic path. The first time it aborts, and the second time it displays without error.

Of the most recent customer test logging, there were 24 attempts to display a document. 13 were successful, and 11 aborted, a 45.83% error rate. This was a much higher failure rate than the previous testing, which was closer to a 5% error rate. This test included additional writes to the log table to precisely identify the line of code where the abort occurs, and we also added GarbageCollect() statements prior and subsequent to the retrieval logic where the errors occur.

Logic path 1 (no setredraw): 11 attempts, 6 success, 5 aborts

Logic path 2 (with setredraw): 13 attempts, 7 success, 6 aborts

We tried creating the pb.ini file with 

[DataStore Behavior]

UseHwnd=no

but the customer reported the application crashed on the 4th attempt to preview the document.

We have many other customers using the same application, and they have not reported the issue.