Some il2 planes Spitfire5* and H_75A* were not in 3.48,  I get a hard lock up if i edit them into .mis files, il2 freezes in mission generation with error "not integer value"?  all runs fine if i use planes in the allpaints.dcg allpayloads.dcg

Your IL-2 version has to match the DCG files you are running. I use CUP - so for that I use 3.49(latest beta) with the necessary dcg files that have the correct aircraft. DCG files have stock aircraft - so as long as you stick with those aircraft in DCG, there will be no issue.

I am using dcg 3.48 and il2 4.12 the spitfireV's and Hawk75's work in il2 but the DCG .dcg doesn't have them.  Probably fixed in 3.49 but just thought i'd say they were'nt in 3.48 just in case