Cannot move issue

Summary

I am trying to move an issue to another project I own, in the same group.

Here is the issue: wp-customerarea/plugins/customer-area#331 (moved)

Steps to reproduce

Click on move > select the destination project > click on move button

The error says "An error occurred while moving the issue"

Relevant logs and/or screenshots

Here is the info I got about the ajax request and response using developer mode for Firefox

Payload: {"move_to_project_id":14347543}

Response code: 500 Internal Server Error

I have not much information apart from that.