At Gen 8.6 PTF level WKS86200 the Diagram Trace Utility (DTU) was running successfully.
However, after the installation of 8.63 Consolidation PTF WKS86300 the DTU attempted startup fails and a DiagramTrace dialog box appears with message:
An error has occurred. See the log file C:\Users\UserID\AppData\Local\CA\Gen 8.6\cfg\DiagramTrace\workspace\.metadata\.log
Consolidation PTF WKS86300 includes fixes from 2 RTN862* PTFs which update the DTU under the directory "%Gen86%\Gen\dt":
a. The PTF RTN86203/SS10543 contained a new version of the DTU built for Eclipse 4.9 build. The install completely moves/backs up the directory "%Gen86%\Gen\dt" and replaces it with the contents of a file DiagramTrace.zip (part of the PTF). That zip file contains files dated October 2019 and because of the complete directory move, no older files dated 2016 should remain.
b. The PTF RTN86214/LU00601 contained a later security update to replace 2 jar files in the directory "%Gen86%\Gen\dt\plugins" :
Those files are dated April 2021
Those updates mean the new files are incompatible with the existing DTU cache located under its temporary work directory "C:\Users\USERID\AppData\Local\CA\Gen 8.6\cfg\DiagramTrace".
Rename the temporary work directory "C:\Users\USERID\AppData\Local\CA\Gen 8.6\cfg\DiagramTrace" to clear the current DTU cache and resolve the problem.