Quartz ObjectAlreadyExistsException exception on MS SQL Server

When the customer was trying to access the homepage, they got the following exception:

com.atlassian.confluence.setup.SpringSessionInViewFilter.sessionFactory : true

• javax.servlet.error.exception : org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'scheduler' defined in resource [/WEB-INF/schedulingSubsystemContext.xml] of ServletContext: Initialization of bean failed; nested exception is org.quartz.ObjectAlreadyExistsException: Unable to store Trigger with name: 'backupTrigger' and group: 'DEFAULT', because one already exists with this identification.
• javax.servlet.error.message :
• javax.servlet.error.request_uri : /confluence/homepage.action