Backup Exec 2012 - No Media error when media is available

[MBALL]

I'm getting an alert on my backup that says, "Please insert overwritable media into the robotic librarty using the import command." 

My job is set to keep data for 4 weeks.  When I go into my media set for keep data for 4 weeks I have a tape that's overwrite protection period is overwriteable.  Any thoughts on my BE isn't picking that tape up and writing to it?

*Note: all my other tapes are still within their overwrite protecion period.

Thanks in advance for your help.

[Kiran_Bandi]

Is the media overwritable, when the job started? Media might became overwritbale after the job started, hence BE asking you to import overwritable media.