# Bug OP-6115 - Gantt: Can't move WP on time axis if follower has no finish date

Project: OpenProject
Status: closed
URL: https://community.openproject.org/work_packages/OP-6115

## Open points

_No work packages_

## Details

| Attribute | Value |
| --- | --- |
| Date |  |
| Priority | Medium |
| Module |  |
| Target versions | 10.0.0 |
| Observed in versions | 10.5.0 |
| Sprint | 10.0.0 |
| Backlog bucket |  |
| Bug found in version (deprecated) | 10.5.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**:

release/9.1

**Logs**

``` logs
app/services/work_packages/set_schedule_service.rb:155:in `reschedule_by_delta'
app/services/work_packages/set_schedule_service.rb:130:in `reschedule_by_follows'
app/services/work_packages/set_schedule_service.rb:96:in `reschedule'
app/services/work_packages/set_schedule_service.rb:81:in `block in schedule_following'
app/services/work_packages/schedule_dependency.rb:49:in `block in each'
app/services/work_packages/schedule_dependency.rb:45:in `each'
app/services/work_packages/schedule_dependency.rb:45:in `each'
app/services/work_packages/set_schedule_service.rb:80:in `schedule_following'
app/services/work_packages/set_schedule_service.rb:47:in `call'
app/services/work_packages/update_service.rb:168:in `reschedule'
app/services/work_packages/update_service.rb:153:in `reschedule_related'
app/services/work_packages/update_service.rb:86:in `update_dependent'
app/services/work_packages/update_service.rb:58:in `update'
app/services/work_packages/update_service.rb:47:in `block in call'
app/services/shared/service_context.rb:39:in `block (3 levels) in in_context'
app/models/journal_manager.rb:384:in `with_send_notifications'
app/services/shared/service_context.rb:38:in `block (2 levels) in in_context'
app/models/user.rb:686:in `execute_as'
app/services/shared/service_context.rb:37:in `block in in_context'
app/services/shared/service_context.rb:36:in `in_context'
app/services/work_packages/update_service.rb:46:in `call'
lib/api/v3/utilities/endpoints/bodied.rb:95:in `process'
lib/api/v3/utilities/endpoints/bodied.rb:69:in `block in mount'

```

**Steps to reproduce:**

1.  Create two work packages
2.  Create follows/precedes relationship between them
3.  Remove finish date from follower
4.  In Gantt chart try to move preceding WP

### **Actual Behavior**

Backend throws error (see log above)

![](/api/v3/attachments/16147/content)

### **Expected Behavior**

I don't expect that the follower's finish date is necessary for establishing a healthy follows/precedes relationship.