If we go back to this PR from @web-padawan, it works again!

IBM/pwa-lit-template#64

In this PR we defer setting outlet until app-index is rendered.

Thanks for the issue. Do I understand correctly that my PR introduced a regression which only reproduces in old Edge?

I would appreciate a reduced test case that would help us to pinpoint the actual bug.

Exactly!

If we go back with this changes (revert-router branch), it works again:

Logging the __ensureOutlet method.

console.log('__ensureOutlet', outlet);

Chrome:

Edge:

Any news about this from the Vaadin team?

Hi @abdonrd, do I understand correctly that this error only happens in legacy browsers? If this is the case, unfortunately, we decided to align the browser support with Vaadin, which means that we won't fix if the bug is only on old Edge. But if it also happens on the latest Edge, then we definitely should fix it.

We found out because Rendertron stopped working for us.

And we have been able to reproduce it in browsers such as:

Since I see movement in the project... (thanks! 🎉 )

@Haprog @platosha @vlukashov @haijian-vaadin could you help us with this?
We have a proposal here: IBM/pwa-lit-template#179

Thanks in advance!

Did I understand right that this affects only old Edge (non-Chromium)? And maybe IE11?
And there is a workaround that works?

I think it's unlikely that we would fix this since we're now targeting support for modern browsers only. See https://github.com/vaadin/vaadin-router/pull/548/files#diff-b335630551682c19a781afebcf4d07bf978fb1f8ac04c6bf87428ed5106870f5

@Haprog we found out because Rendertron (puppeteer & chrome-launcher) stopped working for us since IBM/pwa-lit-template#64.

And we have been able to reproduce it in browsers such Edge, but I'm not sure.

A workaround that seems to work is IBM/pwa-lit-template#179.