At undefined point, I started to get errors when I try to edit the optionset or add anew one:
Notice: Undefined property: stdClass::$imagestyle_normal en flexslider_form_optionset_edit() (línea 420 de ***sites/all/modules/flexslider/flexslider.admin.inc). Notice: Undefined property: stdClass::$imagestyle_thumbnail en flexslider_form_optionset_edit() (línea 428 de ***sites/all/modules/flexslider/flexslider.admin.inc).
This is a weird behaivor because I created the optionset months ago and with no problems. I didn't update the flexslider module at any time between optionset creation and get this errors. It makes me think that this error is generated by some other module outside flexslider. But I can't figure wich of them can be the issue generator.
Googling the error throws this recent generated issue that seems related to this issue.
I tried to figure what is the error but I can't get it. The result of this is that I can't edit or create an optionset, but a previous configured ones seems to work normally.
Any help will be very appreciated. Thanks!