Hi @rupalidaniel!
The most common cause of this problem is that some files are missing, so first you should try a reinstallation. Go to your Plugins list, delete your Smart Slider and install it again, maybe from FTP this time:
https://smartslider.helpscoutdocs.com/article/1717-wordpress-installation#ftp
as that way you can be sure with for example Filezilla, that all your files are getting uploaded.
If this won’t help, you should follow these instructions:
https://smartslider.helpscoutdocs.com/article/1949-error-reporting#error-wp
to enable error reporting on your server. This will create a log file and it will also try to write out the real error into your crashed website. You should search for a “Fatal error” message. If you found it, please tell me what it is!
