I played HC'97 20-25 years ago and loved it. I completed a good chunk of the scenarios and battlesets back then. I noticed a few weeks ago that it was available on Steam, so I purchased it for nostalgia's sake. I completed all of the GIUK scenarios from the first battleset and moved on to the NACV battleset. Here is where I am running into issues. All three of the Okean class vessels in the first two scenarios are replaced with Kalinin class vessels. It is very odd to have a cruiser sailing solo with no escorts. It also causes severe imbalance issues, making the scenarios completely impossible for US/Blue and unenjoyable/non-challenging for USSR/Red. After doing a search in this forum for Okean, I learned that it is also used in the "Ambush" scenario of the NACV battleset. I checked that, and sure enough that has the same issue with Kalinin class instead of Okean class. I'm not sure what other scenarios use Okean class vessels, but my guess is that at minimum, every scenario from the NACV battleset that uses Okean class vessels will have that error. I looked up the individual ship names all of those "Kalinin" class ships were actual Okean class vessels - Repiter, Reduktor, and Zond - also confirming the error or bug.
The Steam version was automatically updated to 1.63d. Is this a known issue with HC'97 or is it something unique to the Steam version? Is anyone aware of a fix?