[Plugin: Highslide 4 WordPress *reloaded*] Missing buttons on Nextgen gallery highslide

Suddenly I am missing overlay buttons when I click an image in Nextgen gallery. The Arrows, Play and so on. The white overlay is shown just not the buttons. Any ideas? Tried uninstalling and reinstalling the plugin but same issue

https://www.ads-software.com/extend/plugins/highslide-4-wordpress-reloaded/