Fatal: Cannot unset string offsets…class-wis_instagram_slider.php on line 844

Fatal error: Uncaught Error: Cannot unset string offsets
in /nas/content/live/domain/wp-content/plugins/instagram-slider-widget/includes/class-wis_instagram_slider.php on line 844

Call stack:

WIS_InstagramSlider::display_images()
wp-content/plugins/instagram-slider-widget/includes/class-wis_instagram_slider.php:450
WIS_InstagramSlider::instagram_images()
wp-includes/class-wp-hook.php:287
WP_Hook::apply_filters()
wp-includes/class-wp-hook.php:311

I haven’t dug into why, just documenting.

FYI, PHP 7.3, everything else current and normal.