diff --git a/src/compiler/GF/Compile/Compute/ConcreteNew.hs b/src/compiler/GF/Compile/Compute/ConcreteNew.hs
index ea55e77cb..6f00c45e1 100644
--- a/src/compiler/GF/Compile/Compute/ConcreteNew.hs
+++ b/src/compiler/GF/Compile/Compute/ConcreteNew.hs
@@ -528,7 +528,7 @@ value2term' stop loc xs v0 =
 --  VGlue v1 v2    -> Glue (v2t v1) (v2t v2)
 --  VExtR v1 v2    -> ExtR (v2t v1) (v2t v2)
     VError err     -> return (Error err)
-    _              -> bug ("value2term "++show loc++" : "++show v0)
+  
   where
     v2t = v2txs xs
     v2txs = value2term' stop loc
diff --git a/src/compiler/GF/Grammar/Canonical.hs b/src/compiler/GF/Grammar/Canonical.hs
index 4adff02f2..0df3236ff 100644
--- a/src/compiler/GF/Grammar/Canonical.hs
+++ b/src/compiler/GF/Grammar/Canonical.hs
@@ -265,7 +265,6 @@ instance PPA LinPattern where
       RecordPattern r -> block r
       TuplePattern ps -> "<"<>punctuate "," ps<>">"
       WildPattern     -> pp "_"                
-      _ -> parens p
 
 instance RhsSeparator LinPattern where rhsSep _ = pp "="
 
diff --git a/src/compiler/GF/Server.hs b/src/compiler/GF/Server.hs
index c287e8001..2e8b8b056 100644
--- a/src/compiler/GF/Server.hs
+++ b/src/compiler/GF/Server.hs
@@ -6,7 +6,7 @@ import qualified Data.Map as M
 import Control.Applicative -- for GHC<7.10
 import Control.Monad(when)
 import Control.Monad.State(StateT(..),get,gets,put)
-import Control.Monad.Error(ErrorT(..),Error(..))
+import Control.Monad.Except(ExceptT(..),runExceptT)
 import System.Random(randomRIO)
 --import System.IO(stderr,hPutStrLn)
 import GF.System.Catch(try)
@@ -108,9 +108,9 @@ handle_fcgi execute1 state0 stateM cache =
 
 -- * Request handler
 -- | Handler monad
-type HM s a = StateT (Q,s) (ErrorT Response IO) a
+type HM s a = StateT (Q,s) (ExceptT Response IO) a
 run :: HM s Response -> (Q,s) -> IO (s,Response)
-run m s = either bad ok =<< runErrorT (runStateT m s)
+run m s = either bad ok =<< runExceptT (runStateT m s)
   where
     bad resp = return (snd s,resp)
     ok (resp,(qs,state)) = return (state,resp)
@@ -123,12 +123,12 @@ put_qs qs = do state <- get_state; put (qs,state)
 put_state state = do qs <- get_qs; put (qs,state)
 
 err :: Response -> HM s a
-err e = StateT $ \ s -> ErrorT $ return $ Left e
+err e = StateT $ \ s -> ExceptT $ return $ Left e
 
 hmbracket_ :: IO () -> IO () -> HM s a -> HM s a
 hmbracket_ pre post m =
     do s <- get
-       e <- liftIO $ bracket_ pre post $ runErrorT $ runStateT m s
+       e <- liftIO $ bracket_ pre post $ runExceptT $ runStateT m s
        case e of
          Left resp -> err resp
          Right (a,s) -> do put s;return a
@@ -407,9 +407,6 @@ resp404 path = Response 404 [plain,xo] $ "Not found: "++path++"\n"
 resp500 msg  = Response 500 [plain,xo] $ "Internal error: "++msg++"\n"
 resp501 msg  = Response 501 [plain,xo] $ "Not implemented: "++msg++"\n"
 
-instance Error Response where
-  noMsg = resp500 "no message"
-  strMsg = resp500
 
 -- * Content types
 plain = ct "text/plain" ""
diff --git a/src/compiler/SimpleEditor/JSON.hs b/src/compiler/SimpleEditor/JSON.hs
index 8f607dc84..06586c5eb 100644
--- a/src/compiler/SimpleEditor/JSON.hs
+++ b/src/compiler/SimpleEditor/JSON.hs
@@ -9,14 +9,24 @@ instance JSON Grammar where
   showJSON (Grammar name extends abstract concretes) =
     makeObj ["basename".=name, "extends".=extends,
              "abstract".=abstract, "concretes".=concretes]
+  readJSON = error "Grammar.readJSON intentionally not defined"
 
 instance JSON Abstract where
   showJSON (Abstract startcat cats funs) =
     makeObj ["startcat".=startcat, "cats".=cats, "funs".=funs]
+  readJSON = error "Abstract.readJSON intentionally not defined"
 
-instance JSON Fun   where showJSON (Fun   name typ) = signature  name typ
-instance JSON Param where showJSON (Param name rhs) = definition name rhs
-instance JSON Oper  where showJSON (Oper  name rhs) = definition name rhs
+instance JSON Fun where 
+  showJSON (Fun   name typ) = signature  name typ
+  readJSON = error "Fun.readJSON intentionally not defined"
+
+instance JSON Param where 
+  showJSON (Param name rhs) = definition name rhs
+  readJSON = error "Param.readJSON intentionally not defined"
+
+instance JSON Oper where 
+  showJSON (Oper  name rhs) = definition name rhs
+  readJSON = error "Oper.readJSON intentionally not defined"
 
 signature  name typ = makeObj ["name".=name,"type".=typ]
 definition name rhs = makeObj ["name".=name,"rhs".=rhs]
@@ -26,12 +36,15 @@ instance JSON Concrete where
     makeObj ["langcode".=langcode, "opens".=opens,
               "params".=params, "opers".=opers,
              "lincats".=lincats, "lins".=lins]
+  readJSON = error "Concrete.readJSON intentionally not defined"
 
 instance JSON Lincat where
   showJSON (Lincat cat lintype) = makeObj ["cat".=cat, "type".=lintype]
+  readJSON = error "Lincat.readJSON intentionally not defined"
 
 instance JSON Lin where
   showJSON (Lin fun args lin) = makeObj ["fun".=fun, "args".=args, "lin".=lin]
+  readJSON = error "Lin.readJSON intentionally not defined"
 
 infix 1 .=
 name .= v = (name,showJSON v)
diff --git a/src/runtime/haskell/Data/Binary/Builder.hs b/src/runtime/haskell/Data/Binary/Builder.hs
index b69371f0e..a74428f20 100644
--- a/src/runtime/haskell/Data/Binary/Builder.hs
+++ b/src/runtime/haskell/Data/Binary/Builder.hs
@@ -68,7 +68,7 @@ import qualified Data.ByteString.Lazy as L
 import Data.ByteString.Base (inlinePerformIO)
 import qualified Data.ByteString.Base as S
 #else
-import Data.ByteString.Internal (inlinePerformIO)
+import Data.ByteString.Internal (accursedUnutterablePerformIO)
 import qualified Data.ByteString.Internal as S
 --import qualified Data.ByteString.Lazy.Internal as L
 #endif
@@ -199,7 +199,7 @@ defaultSize = 32 * k - overhead
 
 -- | Sequence an IO operation on the buffer
 unsafeLiftIO :: (Buffer -> IO Buffer) -> Builder
-unsafeLiftIO f =  Builder $ \ k buf -> inlinePerformIO $ do
+unsafeLiftIO f =  Builder $ \ k buf -> accursedUnutterablePerformIO $ do
     buf' <- f buf
     return (k buf')
 {-# INLINE unsafeLiftIO #-}
diff --git a/src/runtime/haskell/Data/Binary/Get.hs b/src/runtime/haskell/Data/Binary/Get.hs
index 01561d7d9..54f17ae95 100644
--- a/src/runtime/haskell/Data/Binary/Get.hs
+++ b/src/runtime/haskell/Data/Binary/Get.hs
@@ -423,7 +423,7 @@ readN n f = fmap f $ getBytes n
 getPtr :: Storable a => Int -> Get a
 getPtr n = do
     (fp,o,_) <- readN n B.toForeignPtr
-    return . B.inlinePerformIO $ withForeignPtr fp $ \p -> peek (castPtr $ p `plusPtr` o)
+    return . B.accursedUnutterablePerformIO $ withForeignPtr fp $ \p -> peek (castPtr $ p `plusPtr` o)
 {- INLINE getPtr -}
 
 ------------------------------------------------------------------------
diff --git a/src/runtime/haskell/PGF/TypeCheck.hs b/src/runtime/haskell/PGF/TypeCheck.hs
index 5db4ef439..c5cc44b4e 100644
--- a/src/runtime/haskell/PGF/TypeCheck.hs
+++ b/src/runtime/haskell/PGF/TypeCheck.hs
@@ -41,7 +41,7 @@ import Control.Applicative
 import Control.Monad
 --import Control.Monad.Identity
 import Control.Monad.State
-import Control.Monad.Error
+import Control.Monad.Except
 import Text.PrettyPrint
 
 -----------------------------------------------------
diff --git a/src/server/PGFService.hs b/src/server/PGFService.hs
index 3f5307571..260c2e278 100644
--- a/src/server/PGFService.hs
+++ b/src/server/PGFService.hs
@@ -1032,6 +1032,7 @@ instance JSON PGF.Trie where
     showJSON (PGF.Ap f [[]]) = makeObj ["fun".=f] -- leaf
 --  showJSON (PGF.Ap f [es]) = makeObj ["fun".=f,"children".=es] -- one alternative
     showJSON (PGF.Ap f alts) = makeObj ["fun".=f,"alts".=alts]
+    readJSON = error "PGF.Trie.readJSON intentionally not defined"
 
 instance JSON PGF.CId where
     readJSON x = readJSON x >>= maybe (fail "Bad language.") return . PGF.readLanguage