Moving issues across kanban backlog throws an error

Issue Summary

Moving issues with assigned epic across kanban backlog and divided kanban backlog area is throwing a javascript error. Problem occurs on kanplan, I couldn't reproduce it on scrum backlog. After first occurrence an error will be thrown for each drag & drop. The core functionality of dragging issues works but the usability of it is pretty low and may have side effects.

Environment

• macOS Mojave 10.14
• Google Chrome 72

Steps to Reproduce

1. Create a kanban project
2. Enable kanplan
3. Get a backlog of variety issues (with and without epic).
4. Try to move an issue with assigned epic to divided kanban backlog area
5. After D&D javascript error will throw

Expected Results

Moving issues across kanban backlog works without errors. 

Actual Results

The below exception is thrown:

Exception: Uncaught TypeError: Cannot read property 'text' of undefined

Notes

It works properly on 7.13.x

Workaround

Currently there is no known workaround for this behavior. A workaround will be added here when available