BlackSix, COOPs is the No.1 missing feature as voted on IL2bugtracker
http://www.il2bugtracker.com/project...ues?query_id=1
It was extremely popular in original Il-2 and absent now in spite of "coop" folder shown in the MP mission selection menu ( \1C SoftClub\il-2 sturmovik cliffs of dover\missions\Multi\Co-Op ).
COOP fix is not related to crashes, graphics, FM or AI and can be programmed by different people I guess. This will not slow down the patch development.
Could you please ask Luthier for the next info-update when we will see COOPs fixed in ClOD? I do not think he would ignore the most wanted feature by community.
Details of required COOP fixes are listed on the bugtracker.