Transaction Log Policy is not running.

I am using Net Backup 6.5.2A i need to take Transaction Logs backup for a MS SQL Database.
I tried a bch file for the same, while running that it is giving me a error.

Please fine the error message and help how to resolve this issue.

OPERATION BACKUP
DATABASE "SOL"
SQLHOST "XXXX"
NBSERVER "XXXX"
MAXTRANSFERSIZE 6
BLOCKSIZE 7
POLICY SOL_TR
OBJECTTYPE TRXLOG
NUMBUFS 2
ENDOPER TRUE

USER - Operation inhibited by NetBackup for Microsoft SQL Server: Only a full or incremental database backup can be performed on database <SOL> because it uses the simple recovery model or has 'truncate log on checkpoint' set.
INF - OPERATION #1 of batch C:\Program Files\Veritas\NetBackup\dbext\mssql\temp\__19_58_35_495_00.bch FAILED with STATUS 1 (0 is normal). Elapsed time = 7(7) seconds.
INF - Results of executing <C:\Program Files\Veritas\NetBackup\dbext\mssql\temp\__19_58_35_495_00.bch>:
<0> operations succeeded. <1> operations failed.
INF - The following object(s) were not backed up successfully.
INF - SOL


Thanks