How to fix ‘Fatal error: Class ‘Mobile_Detect’ not found ” error in PHP Melody theme installation

I have followed the instructions on ‘Essence User manual.pdf’

1) Uploaded all the below files to PHP Melody website in the appropriate directories.

include
players
plugins
templates

2. Activated the plugin by login to the admin panel

Once the plugin activated, below error showed on both front and back end.

Fatal error: Class 'Mobile_Detect' not found - PHP Melody

Then I deactivated the plugin thorugh phpmyadmin – > mm_plugins – > Edit – > active -> change value 1 to o

After doing that, I got another error as:

Fatal error: Smarty error: [in index.tpl line 23]: [plugin] modifier 'gethdthumb' is not implemented

Now I’ve reactivated the plugin through admin area and downloaded fresh copy of ‘mobile_detect.php’ file and uploaded to include folder.

That resolved the issue and everything seems working fine now.