Introduction

Different causes can lead to the game data getting corrupted or being missing. This can also be caused by different situations like (non-concluding list):

• running out of disk space when updating/installing the game
• disk corruption
• malware infection
• manually removing or modifying game data
• 3rd-party tools damaging the data

Game data verification using Steam or GOG

Fortunately GOG and Steam both provide means to fix the broken installation without having to download the entire game again. The following instructions show how you can do this.

Steam client

1. In the Steam client go to the LIBRARY tab [1], right click on the X4: Foundations entry [2] and select: Properties [3]
   
2. In the next window select the LOCAL FILES [1] tab and click on VERIFY INTEGRITY OF GAME FILES... [2]
   

...

Afterwards any missing or broken game files should have been restored/corrected.

GOG

1. In the GOG Galaxy client click on X4: Foundation [1] , click on MORE [2], select Manage installation [3], and click on Verify / Repair ... [4]
   
2. In the new popup, click on VERIFY GAME [1]
   

...