Windows has a maximum path length of 260 characters (by default). Nested mod folders like: C:\Users\YourName\Documents\Paradox Interactive\Hearts of Iron IV\mod\MyHugeOverhaul\gfx\fonts\russian\code-pre-gfx.bmp This can easily exceed 260 characters, causing a "file not found" error disguised as a read error.
If a simple repair fails, you may need to manually delete the corrupted index files to force a full re-verification: Go to the game directory and delete everything folder and the launchers. Inside the folder, delete the subfolders. Scan and Repair from your game client again. 4. Graphic Setting Adjustments read error of file rus code-pre-gfx