Hi @webmestre,
Which version of Drupal you have used while using manual crop ...

Hi @webmestre,

Which version of Drupal you have used while using manual crop module, so that I can repopulate and check?

I have used the manual crop 7.x1.7 for the Drupal 7.60 version and tested the module, by adding the images styles which is working fine for me.
I have even checked the paths:
- admin/config page - same for admin/reports/status
- content/edit pages which does not displays a white page for me.