ORA-00001: unique constraint (OP.JOBS_PK) violated

Hi,

we migrated a table with expdp , impdp from v11.2.4 to 12.1.02 on linux RH 6.4. By starting the Application again we get  ORA-00001: unique constraint (OP.JOBS_PK) violated on the

table OP.JOBS:

questions:

1) is the ID value created and incremented by the system ? 

2) How can I verify with  SQL that the next system counter value given to the ID Primary Key colum is higher than 2443568.

3) Do you have additiona hints to identify the problem?

thanks a lot. regards 

Giorgio

Definitions of OP.JOBS

column name : ID number size 12 not null

constraints : JOBS_PK, Type Primary  table column : ID  Validate :YES