Cannot perform a differential backup for database "", because a current database backup does not exist.

There are many scenarios where in you might come across a Differential Backup Job failed with following error.

"Cannot perform a differential backup for database "", because a current database backup does not exist.Perform a full database backup by reissuing BACKUP DATABASE, omitting the WITH DIFFERENTIAL option.  BACKUP DATABASE is terminating abnormally."

You may say that, my full backup Job runs first and then the differential job, then how come I got this error. One of the case might be you are using a Maintenance Plan or a SSIS Package to run your Backup Jobs. You have scheduled it through SQL Server Agent.

Ex: Full backup Runs every Night 1 AM, Differential Backup runs every 3 hours.

Now 1 AM your backup Job has taken Full Backup of all databases on Instance. Now You create a  New database at 2 am, now when at 3 AM your differential backup runs, it wont find the full backup for that database which will happen only on next day 1 AM, so it throws the above error.

This will resume to normal after a Full backup is issued.