Hi honzas,
Try this way
1. Open file "\CuteSoft_Client\Gallery\Editor\Explorer\Code.js"
2. Find section below
var uploadbtn=CreateEditorButton("Images/standard-upload.png",GalleryLocalize.CLICK_UPLOADFILES);
3. Change to
var uploadbtn=CreateEditorButton("Images/standard-upload.png",GalleryLocalize.CLICK_UPLOADFILES);
uploadbtn.style.display="none";
4. Find section below
5. Change to
uploadbtn.style.display="";
var div=null;
6. Now, the upload button will not be displayed until you select a category.
Regards,
ken