Class ItemIcon2 not found
Error message
Fatal error: Uncaught Error: Class 'Nextend\SmartSlider3Pro\Renderable\Item\Icon2\ItemIcon2' not found
Cause
The cause of this problem is that you are using GIT. GIT has a default gitignore file with these codes in it:
# OS generated files # ###################### .DS_Store* ehthumbs.db Icon? Thumbs.db ._*
which was made to ignore some files from being uploaded. The Icon? line makes every file and folder to be excluded from your uploading, which starts with the word "Icon", so you should just remove this line from your gitignore file, upload your files again and everything should be fine!
You can check whether or not you have this folder, to confirm that the issue has been resolved:
WordPress:
\wp-content\plugins\nextend-smart-slider3-pro\Nextend\SmartSlider3Pro\Renderable\Item\Icon2\
Joomla:
\libraries\smartslider3\src\SmartSlider3Pro\Renderable\Item\Icon2\