Unable to delete old Backup Job

Hello,

At my company we are running Backup Exec 2012 on a Windows 2008 server. Now there are two old jobs that I want to delete from the job list. But every time I want to delete them, I get the following error:

I have searched the almighty Google but all the solution there aren't working. Even from the BECLI I get the same error.

Is there anyone that can give me a solution to this problem?