^Unfortunately, putting both freearc.exe and xtool.exe into registry like above did not help.
err.png
EDIT: Not all reflate are broken, in fact many are fine. I am starting to see potential pattern but will confirm it later whether its case. Ones with the issue so far are the ones with custom settings, like chunk size
-c32m etc., whereas all the good ones are just default
-mxtool:reflate so far.
EDIT2: I see the pattern. This error affect both reflate and zlib,
when high chunk size(>32mb) is used. This was working fine on Win7. Changing thread number doesn't seem to cut it. And I have same rig with enough memory(16G). I will try few more things but it seems as if Win8.1 is handling memory or relevant functions differently.
EDIT3: Windows 7 under Hyper-V did not help. I still believe archives are good and this is because I don't run under native.