Duplicate key value violates unique constraint

Hi support,

I migrate my data from MS Sql server to postgreSQL database, now when I try to insert new row it gives me error “duplicate key value violates unique constraint”. For example I have a table which contains 100 rows of records when I go for inserting 101 row it give duplicate value constraint error. When I pass PK value manually its working, and one more thing auto increment is enabled for all tables .

Can you please let me know anything I am missing?  I will really appreciate it.

Thanks

Regards

Nafees Sardar