Cannot get into Campaign mission #4 - 24th May 2020

[Paddy]

There were quite a few of us this evening that could not get into the server; my squadron plus others.

Symptoms
- Game hangs for quite some time on downloading files
- Screen can go black but never changes to map view to choose spawn

Fix
- Shutdown BoS
- Goto BoS install directory\data\Multiplayer\dogfight. Delete ACG campaign mission folders and files (probably only needs to be the current one).
- Goto BoS install directory\data, delete ctreecache.eng and mtreecache.eng
- Start BoS again, et voila

I'm not saying this is a silver bullet but it worked for pilots in our squadron.