The design of the Symfony exception pages hasn't been updated in years. After the Symfony Profiler redesign introduced in Symfony 2.8, updating their design is more needed than ever.

I've created this issue to tell you that we've already started working on this and that we'll show the result in a few days, after the SymfonyCon Berlin so the community can provide feedback about it. Meanwhile, please try to not change anything related to those pages. Thanks!