In a winforms application, with sdf database, I try to run a migration and return exception when update-database System.Data.SqlServerCe.SqlCeException (0x80004005): A duplicate value cannot be inserted into a unique index. [ Table name = __MigrationHistory,Constraint name = PK_dbo.__MigrationHistory ] , If I run again this command then it runs succesfully. In up method I try to add an object in database with entity framework. But migration seems that it try to run twice. How I can solve this problem?

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