Is there anything in Tracing Exceptions, Crashes and Freezes - Overview, that is able to help you?
"It is quite possible that the tested application stops responding to user actions and to the operating system’s messages. This may cause your tests and TestComplete to hang. A typical example of the situation is when you test an Open Application, call the application’s internal method from your script code or keyword test, and the method never returns a result (for instance, it goes into an infinite loop). In this case, TestComplete also gets hung up, because it waits for the method’s result and does not proceed with the test execution." - could it be ReactJS / Electron control not responding correctly?