Mount & Blade II: Bannerlord players have recently reported a frustrating issue — the game suddenly crashes when clicking on the Diplomacy tab in the kingdom menu. Whether you’re running a modded or vanilla version, this error can appear unexpectedly and disrupt your campaign. Let’s go through the possible causes and proven fixes for this crash.
Table of Contents
Common Causes of the Diplomacy Tab Crash
The Diplomacy tab pulls data from multiple systems — factions, relations, and ongoing wars. When one of those data sources is corrupted or missing, the game crashes. Here are the most common reasons:
Mod conflicts (especially with diplomacy or kingdom overhaul mods)
Corrupted save files after major updates
Old mods not updated for the latest game version
Incomplete game files or broken configuration data
Custom settlements or factions created by mods that no longer exist in the save
Step-by-Step Fixes
1. Check for Mod Conflicts
If you use mods like Diplomacy Fixes, Diplomacy Expanded, Kingdom Reforms, Banner Kings, etc., try these steps:
Disable all diplomacy or kingdom-related mods.
Restart the game and load your save.
If the crash disappears, enable mods one by one to find the culprit.
💡 Tip: Mods that alter the kingdom interface or add new factions are the most likely cause.
2. Verify Game Files (Steam / Epic)
Corrupted or outdated files can also trigger the crash.
Steam:
Right-click Mount & Blade II: Bannerlord → Properties
Go to Installed Files → Click Verify integrity of game files
Epic Games:
Click the three dots next to the game
Choose Manage → Verify Files
This process checks for missing or corrupted files and replaces them automatically.
3. Clean Up Config Files
Old configuration data may interfere after patches.
Navigate to:
Documents\Mount and Blade II BannerlordBackup and then delete the Configs folder
Relaunch the game — it will rebuild clean configuration files.
4. Load a Backup Save
If you started your campaign in an older patch (e.g., 1.1.5 or 1.2.x) and continued into 1.3.0+, your save may not be fully compatible.
Try loading an earlier save file before the first crash occurred.
⚠️ If the game crashes before loading, disable all mods first, then try again.
5. Check Known Mod Conflicts
Some popular mods reported to cause this issue (as of October 2025):
Diplomacy (Expanded) – older versions cause tab crashes in 1.3.0+
Banner Kings – when used with Diplomacy or Kingdom Reforms
Calradia Expanded: Kingdoms – sometimes breaks faction data
Persistent Kingdoms – may cause null reference crashes in the diplomacy menu
Always download the latest compatible versions for your Bannerlord build from Nexus Mods.
Additional Tips
Avoid mid-save updates. Starting a new campaign after a big patch (like 1.3.0) is safer.
Use the Developer Console mod (
Ctrl+~) to fix corrupted kingdoms or declare peace manually if diplomacy menus are broken.Keep a rolling backup of your saves (especially before patching or adding mods).
Summary: Quick Fix Checklist
| Problem | Fix |
|---|---|
| Game crashes when opening Diplomacy | Disable diplomacy-related mods |
| Save corrupted | Load backup save / start new campaign |
| Game files broken | Verify files via Steam or Epic |
| Old configs causing issues | Delete Configs folder in Documents |
| Conflict between major mods | Use updated mod versions |
Final Thoughts
Crashes like these are often caused by outdated mods or leftover data from old saves. If you’re playing on the latest version (1.3.0 beta or newer), ensure every mod you use has been updated accordingly.
If the game still crashes even in a clean, unmodded setup — it’s worth submitting your crash report via TaleWorlds Support. They actively patch known issues reported through the official crash reporter.
