Hi - I have an entity declaration in persistent as follows: share [mkPersist sqlSettings { mpsGenerateLenses = True, mpsPrefixFields = False }, mkMigrate "migrateAll"] [persistLowerCase| Account accountNo Text accountType AccountType accountHolderName Text accountOpenDate UTCTime default=CURRENT_TIME accountCloseDate UTCTime Maybe default=NULL currentBalance MoneyUSD rateOfInterest Double Primary accountNo deriving Show |] I am getting this compilation error .. • No instance for (Generic (Key Account)) arising from the 'deriving' clause of a data type declaration Possible fix: use a standalone 'deriving instance' declaration, so you can specify the instance context yourself • When deriving the instance for (aeson-1.4.6.0:Data.Aeson.Types.ToJSON.ToJSON (Key Account)) | 40 | share [mkPersist sqlSettings { mpsGenerateLenses = True, mpsPrefixFields = False }, mkMigrate "migrateAll"] [persistLowerCase| | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^... and another exactly similar for FromJSON What exactly is going wrong here ? I am not using json in the above definition. regards. -- Debasish Ghosh http://manning.com/ghosh2 http://manning.com/ghosh Twttr: @debasishg Blog: http://debasishg.blogspot.com Code: http://github.com/debasishg