This happens if the folder structure is wrong. Ensure the "english" folder is inside the "zone" directory, not nested inside another folder.
If the "Language" tab is missing or English isn't listed, your version is region-locked, and you will need to use Method 2. Method 2: Manual Installation (For Region-Locked Versions) english+language+pack+for+cod+black+ops+2
Ensure your localization.txt is properly formatted. If it says "russian" or "polish" inside the text file, change it to "english". Is it Safe to Use Language Packs? This happens if the folder structure is wrong
This is usually due to a version mismatch between the language pack and the game executable. Ensure you are using files compatible with the latest version of the game. This is usually due to a version mismatch
Replace the existing localization.txt in the main folder with the English version.
How to Download and Install the English Language Pack for Call of Duty: Black Ops 2