When you say "Earlier there was no such sequence but all my sequences for each table." I assume you mean that you expect your objects to use IDENTITY sequencing.
In previous versions the PostgreSQL platform did not support Sequence Object based native sequencing. TopLink was automatically switching your sequencing configuration to use IDENTITY sequencing on PostgreSQL. In the latest versions TopLink supports both SEQUENCE and IDENTITY sequencing and will use the configuration specified.
If you are using IDENTITY fields but seeing this exception you most likely have your entities configured to use SEQUENCE base sequencing. Changing the appropriate sequences config to use IDENTITY should solve your problem.
--Gordon
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