TypeError: Cannot read property hasTrackId of null

While running locally after upgrading my project form Mendix 6.10.16 to 7.19.1, I am receiving this error after logging into the application and landing on the home page. After closing the default β€œAn error occurred, please contact your system administrator.” error message the app seems to work fine – unless you refresh the browser, in which the error repeats.  Anybody encountered a similar issue? Cannot read property 'hasTrackId' of null TypeError: Cannot read property 'hasTrackId' of null at Object.e.onPersistViewState (http://localhost:8080/mxclientsystem/mxui/mxui.js?636851349496725645:82:61199) at Object.<anonymous> (http://localhost:8080/mxclientsystem/mxui/mxui.js?636851349496725645:82:30827) at w (http://localhost:8080/mxclientsystem/mxui/mxui.js?636851349496725645:51:299728) at Generator._invoke (http://localhost:8080/mxclientsystem/mxui/mxui.js?636851349496725645:51:299516) at Generator.e.(anonymous function) [as next] (http://localhost:8080/mxclientsystem/mxui/mxui.js?636851349496725645:51:299907) at w (http://localhost:8080/mxclientsystem/mxui/mxui.js?636851349496725645:51:299728) at t (http://localhost:8080/mxclientsystem/mxui/mxui.js?636851349496725645:51:300043) at http://localhost:8080/mxclientsystem/mxui/mxui.js?636851349496725645:51:300339 at new Promise (<anonymous>) at o (http://localhost:8080/mxclientsystem/mxui/mxui.js?636851349496725645:51:299990)  
1 answers

Poster found the answer, adding it here to mark the post as answered and future reference:

Thanks to everyone who responded. I found the issue. A show form action was being called twice, once on a subflow and then on the main flow. An over sight that was never an issue before. #facepalm