# Bug OP-9521 - Git "View Differences" results in 500 error in Repository module.

Project: OpenProject
Status: closed
URL: https://community.openproject.org/work_packages/OP-9521

## Open points

_No work packages_

## Details

| Attribute | Value |
| --- | --- |
| Date |  |
| Priority | Medium |
| Module |  |
| Target versions | 12.0.5 |
| Observed in versions | 12.0.0 |
| Sprint | 12.0.5 |
| Backlog bucket |  |
| Bug found in version (deprecated) | 12.0.x |
| Found in mobile app version |  |
| Follow-up feedback e-mail |  |
| Requires doc change | No |
| Accessibility | No |
| Pull preview |  |
| List |  |
| Labels |  |

## People

| Attribute | Value |
| --- | --- |
| Assignee |  |
| Accountable |  |
| Product manager |  |
| Developers |  |
| Designer |  |
| Ordered by |  |
| Signed off by |  |
| Interest by |  |

## Planning

| Attribute | Value |
| --- | --- |
| Relevance |  |

## Costs

| Attribute | Value |
| --- | --- |
| Votes |  |
| Work |  |
| Labor costs |  |

## Description

### **Environment**:

Your OpenProject Version: 12.0.2 / Enterprise Edition (self-hosted, Debian)

Linux / Firefox / English:

### **Logs**

No errors in browser console. 

Corresponding error from \`\`\`` openproject logs```  `

Nov 30 10:28:35 services2 openproject-web-1.service[1377]: E, [2021-11-30T10:28:35.558651 <mention class="mention" data-id="1377" data-type="work_package" data-text="#1377">#1377</mention>] ERROR -- : user=3 undefined method `diff_type' for #<UserPreference:0x00005579b9862aa8>: undefined method `diff_ty  
pe' for \#\<UserPreference:0x00005579b9862aa8\>

### **Steps to reproduce:**

1.  Go to a integrated git repository of a project with multiple revisions
2.  Click on View Differences to get the differences between to revisions

### **Actual Behavior**

An error occurs after clicking View Differences:

<figure class="image op-uc-figure"><div class="op-uc-figure--content"><img class="op-uc-image" src="/api/v3/attachments/23898/content"></div></figure>

### **Expected Behavior**

I would except to be able to compare revisions in Openproject, like it was possible in previous versions