Old JG-51 questions

[Kimmer]

This is the symptom

This is the old forum link 

https://forum.il2sturmovik.com/topic/27131-veteranencampaign-jg51-over-velikie-luki/

I don’t know why I can’t open the mission.

[jokash]

That campaign doesn't work for me (real shame cause its one of the best,it has custom voice lines and lot of detail put into it).I get some error halfway into the mission about some effect error.Its just too old and not updated in long time