Email fail

I am having issues sending email on my remote server, using Sendgrid SMTP. It works locally, but not on the remotes server. When sending a test email on the remote server I get this message:

Fatal error: Class 'PerchSystemEventSubject' not found in /home/forge/newplatespecials.com/public/perch/core/lib/PerchEmail.class.php on line 23

Is this perhaps because version control has missed a file in the Core folder? Double checking the SMTP credentials against local config and all is fine there.