Hi PW,
Thanks for getting in touch.
There were some updates to the underlying image editor code in core WordPress, seemingly introduced in WordPress 4.7 (and 4.5 and 4.6).
Please see this topic for more information regarding the issue that I believe is causing the blank screen:
https://core.trac.www.ads-software.com/ticket/36534
The code around the image editor in Meta Slider has not been changed for a long time now (years) – we use core WordPress functions to crop the images and retrieve image information.
I believe you, and other users, and running into issues which have been introduced since WordPress 4.7. Please try rolling back to an earlier version of Meta Slider to see if you can determine whether this is an issue with a WordPress update or Meta Slider. Details of how to roll back are here: https://www.ads-software.com/support/topic/meta-slider-3-4-update/
In that ticket (https://core.trac.www.ads-software.com/ticket/36534), there are some suggestions of how it might be resolved, but unfortunately there doesn’t seem to be one single fix (if there was, we would implement it ourselves inside the plugin code), it seems different fixes are working for different people.
Regards,
Tom