Maven fight started having invisible walls and then instance crashed

I was doing Maven fight in SSFR. Partway through, some invisible walls started appearing due to an issue with the Bramble Valley boss: https://www.reddit.com/r/pathofexile/comments/1eevk3z/invisible_wall_summoned_by_bramble_valley_boss/

I had two portals left and Maven Brain was mostly dead, so I was looking forward to the clear until the last two portals I had disappeared entirely (I suspect an instance crash). It may be that this boss together with Maven can cause crashes.