Any news on when the GOG version will be fixed so that we can play the latest 1.6 version?

As of now only the 1.5 version is provided as a solution to the the problems with the GOG release earlier.

If tank_warfare_tunisia_1943_1.6_(44464) doesn't start properly, move programs_flatdata to *\Tank Warfare Tunisia 1943 \root

There’s no 1.6 version unless you use the Russian installer. The English version is still on 1.5.