The 40250 wire structs hold Win32 long (4 bytes) sockets; on LP64 `long` is 8, so each TShopItemData was too wide and SHOP_SUBHEADER_GC_START/_EX misread every item after the first. Pin the wire size with a static_assert. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>