I first installed "Afrika Korps", then the two Grand Campaigns and at last patch 1.11. (Win 7/64 bit) Then I started playing the tutorial campaign, because I had never played "Panzer Corps" before. I did not play any other scenarios yet.
The problem occured in the last two scenarios of the tutorial campaign (scenario 5 and 6) with the SdKfz 10/4: no driving sound, no sound while shooting. I can't say, if this problem occurs as well in the previous tutorial scenarios, because I didn't use the SdKfz 10/4 in these scenarios.
What exactly do you mean with "old save game"? I started with v1.11 - so I didn't use any save games of an older version of the game. But yes - I saved the game several times and used these save games. Maybe important: I never used the auto save games.
Thanks for trying to help me!
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Edit: I also tried the following: 1) Loading savegame (beginning of scenario 6, tutorial campaign), 2) Restart of scenario, 3) Deleting old savegame and saving again, 4) Loading new savegame
--> No change: SdKfz 10/4 still without sound