vaadinPush.js?v=7.7.13 could not be loaded. Push will not work.

I’m running on Apache 2.4.34 and Tomcat 5.8.32 and I’m getting the Communication Problem warning with the message: “https://<>/VAADIN/vaadinPush.js?v=7.7.13 could not be loaded. Push will not work.” I’ve checked the deploy and the vaadinPush.js is there. The app works (with the Communication Problem banner constantly displayed) but push is not working.

Anyone have a suggestion on why vaadinPush.js is not loading?

I have same issue.

I think the problem is related to using Apache as a proxy server in front of Tomcat. When I go to Tomcat without Apache I don’t have the error but I can’t figure out how to configure Apache in a way to prevent the error.

I’ve tried following this thread but no luck. Perhaps there’s a dependency that’s being included that’s causing the issue?

I’ve also tried the things discussed in this StackOverflow thread: with no luck.