Pictures disappear from Gallery after downloaded ES File Explorer

[atickass]

I just downloaded ES File Explorer and tried to hide a picture in Whatsapp Images and named it as .nomedia. However, all of my pictures in Whatsapp Images disappeared from Gallery. The folder is still there after I've change the name of the hidden picture, only that hidden picture remains in that folder. But, all of those pictures can be seen in ES File Explorer. Please help.