I am using Dokku to deploy the application on the production server. On some pages, my application crashes with this blue screen:

I logged in on the server and ran dokku log my-app-name with hope I’ll see the error – but unfortunately, there was no error in the log.

Then I looked to /var/log/nginx/my-app-name-error.log – no error caught either, only the last known request before the error happened. Also, I looked to /var/log/nginx.error.log – and again, no error.

I also have integrated Rollbar, but it didn’t catch any error either. Finally, I set config.consider_all_requests_local to true for production in the Rails app, but it didn’t provide any error indication neither.

Any advice how do I find the problem causing the blue screen?