Why is the HangFire startup process failing with this error?

We're seeing this error when starting up a process that uses HangFire (1.6.22) and PostgreSQL.

2019-03-19 00:12:45,406 [1] ERROR
Hangfire.PostgreSql.PostgreSqlStorage [(null)] - Error while executing install/upgrade Npgsql.PostgresException (0x80004005): 42701: column "updatecount" of relation "lock" already exists
    at Npgsql.NpgsqlConnector.<>c__DisplayClass161_0.<<ReadMessage>g__ReadMessageLong|0>d.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
    at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
    at Npgsql.NpgsqlConnector.<>c__DisplayClass161_0.<<ReadMessage>g__ReadMessageLong|0>d.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
    at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
    at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
    at System.Runtime.CompilerServices.TaskAwaiter`1.GetResult()
    at Npgsql.NpgsqlDataReader.<NextResult>d__46.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
    at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
    at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
    at Npgsql.NpgsqlDataReader.NextResult()
    at Npgsql.NpgsqlCommand.<ExecuteDbDataReader>d__100.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
    at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
    at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
    at Npgsql.NpgsqlCommand.<ExecuteNonQuery>d__92.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
    at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
    at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
    at System.Runtime.CompilerServices.TaskAwaiter`1.GetResult()
    at Npgsql.NpgsqlCommand.ExecuteNonQuery()

fixed. This may help others , what we did.

The real issue was , when we created Tables for HangFire it was created using SQL scripts that available in source repo. And when code run it found some mismatch and automatically try to update DB tables, and failed.

So we deleted all tables and let HangFire create tables on first run. Now working fine.