How to troubleshoot a web-app that is crashing after running multiple hours

One of our web-apps (written with Scala.js) apparently crashes after running multiple hours (it is supposed to be running on a control cabinet without connection to the internet). I have been told that this application crushes after running roughly 8 hours with an Aww snap, something went wrong displaying the webpage - error message. Refreshing with F5 solves the problem.

For me that sounds like a 'simple' stack overflow error or something similar. Is there any good way of finding this error? This application is quite huge and I could not find the error by just looking at the code, so I have been wondering if there is any clever way of analyzing something like this that I am not aware of?