Blank Page on Live Server but works on localhost?

Under my method in my model, when I redirect on my live host, it goes to a blank page but on my localhost it works perfectly. 

Can someone shed some light on why this is happening and how to fix it ?

It could be a number of thing .htaccess file wrong base_url wrong protocal.

What did you Try? What did you Get? What did you Expect?

Joined CodeIgniter Community 2009.  ( Skype: insitfx )

Most likely there is a PHP error, but your production server is hiding it for security reasons. Check your PHP error log or temporary enable showing of errors.

This is the error and I can't figure out why... 
html/application/vendor/mailgun/mailgun-php/src/Mailgun/Connection/RestClient.php on line 121, referer: http://tesseracts.co/contact

Can someone help ? Been stuck on this for a long time now...

And was is on line 121 thats where the error is.

What did you Try? What did you Get? What did you Expect?

Joined CodeIgniter Community 2009.  ( Skype: insitfx )

The error is in Mailgun, not CI.