Error when importing repositories to a team project

Issue Summary

Add repositories to a project of a team screen is showing an error

Request parameter repo_ids must not be empty 

Originally raised as Community question.

Steps to Reproduce

1. Go to https://bitbucket.org/account/user/<team>/projects/<project_key>
2. Click on Add repositories button in the top right corner
3. Select repositories to add
4. Click Add repositories

Same issue happens when adding repositories from an individual account after the Transfer ownership of repositories dialog is shown.

Expected Results

Repository moved/transferred to the team's project.

Actual Results

Not very useful error shown in the UI. Repositories left intact.

Workaround

Move/transfer each repository via its settings. No bulk move/transfer workaround.