Select all checkbox not working

Just tested select all and it seems to be working fine on 4.2.6.

2 possibilities:

1. You're actually doing something wrong
2. You're not doing anything wrong

Please provide more information on your view config.

I uploaded 2 screenshots and a short video.

Thanks

Tested on a clean instance and the issue from your video doesn't occur.

Please try to do the following:
1. install latest stable Drupal (or the version you have on your project)
2. install VBO
3. Configure a view, try to reproduce your issue
4. Post feedback here.

If you cannot reproduce, the problem is in your custom code / theme.

This seems to be an issue with the Gin theme. We have the same problem and switching to a core theme works as expected. I was not yet able to find the commit/issue that triggered the issue.