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Can we clear up download descriptions a little please GOG, Part 1 & 2 are 64-bit part 3 & 4 are 32-bit, these are the latest release, what is the 32-bit installer is an older build, Rising Sun part 1 (64b) part 2 (32b) 32-bit (older build).

However I have it seems a new issue, installing Rising Sun DLC (all 64-bit) blocks US Pacific campaign and Rising Sun is still not active (still has try & purchase options only), of course I could be more certain in my own competence with better descriptors on site.
It seems I may have been hasty to claim an issue, a reboot resolved and all is well, just the first time this millenium a reboot is the solution for me.