Because s_requestContext was private you couldn't really get the language that was chosen without including the request as argument and then calling the translation context's determine language function.
BTW, I was trying work on the exception issue tonight, but made matters worse for a while. It seems to be back to normal now, but I still get the intermittent failures. I'll have to improve the debug facilities there.
@WebFreak001 he reverse proxy that is in front of the registry process (also implemented with vibe.d) sometimes hangs in exception unwinding code. LDC first seemed to fix that, but it only lasted for a few hours. I'm looking for possible workarounds.