ERROR: Upgrade failed: DB: Duplicate entry

Hi Alec,

I am upgrading my ojs application form 2.4.6 to 3.1.1.2 but while upgrading with command line, I am facing below error
ERROR: Upgrade failed: DB: Duplicate entry ‘2661-3-1’ for key 'review_rounds_sub mission_id_stage_id_round_pkey’

Please suggest me to best way to resolve this problem.

Thank you in Advance.

Avinash K Shukla