Error messages from field groups

Hello,

I have a content type with several fields so I used the grouping field and there the accordeon option.
Trying to change the value of textfields I used modify entity values but it first wouldn't show the textfields for the values to update.

Now, I removed the groups and VBO shows the textfields for changing values.

I still receive errors though:

Notice: Trying to get property of non-object in _field_group_get_html_classes() (line 2057 of /var/www/domain.com/sites/all/modules/field_group/field_group.module).
Notice: Trying to get property of non-object in _field_group_get_html_classes() (line 2059 of /var/www/domain.com/sites/all/modules/field_group/field_group.module).
Notice: Trying to get property of non-object in _field_group_get_html_classes() (line 2063 of /var/www/domain.com/sites/all/modules/field_group/field_group.module).
Warning: Attempt to assign property of non-object in field_group_pre_render_prepare() (line 617 of /var/www/domain.com/sites/all/modules/field_group/field_group.module).
Warning: Attempt to assign property of non-object in field_group_pre_render_prepare() (line 618 of /var/www/domain.com/sites/all/modules/field_group/field_group.module).
Notice: Trying to get property of non-object in field_group_field_group_pre_render() (line 636 of /var/www/domain.com/sites/all/modules/field_group/field_group.module).
Notice: Trying to get property of non-object in field_group_field_group_pre_render() (line 646 of /var/www/domain.com/sites/all/modules/field_group/field_group.module).

Doesn't look nice but it works so far, now without groups.