i understand that the 1.7.10 is not supported but it was working yesterday morning but i tried it later that day and it crashed and i tried it just now no good but then it tried my modpack on a fresh client on the same pc works so can anyone tell me what is making it crash
crash-2017-04-04_10.19.24-client.txt

ok i will try that

thanks it is working

Somebody else had the same issue with newer versions of optifine.
Reverting Optifine to version 1.7.10_HD_U_D4 fixed the problem for him.