diff --git a/src/OpenFOAM/primitives/Scalar/Scalar.C b/src/OpenFOAM/primitives/Scalar/Scalar.C
index cdd94c7b15..4445a52767 100644
--- a/src/OpenFOAM/primitives/Scalar/Scalar.C
+++ b/src/OpenFOAM/primitives/Scalar/Scalar.C
@@ -84,7 +84,7 @@ Istream& operator>>(Istream& is, Scalar& s)
     {
         is.setBad();
         FatalIOErrorIn("operator>>(Istream&, Scalar&)", is)
-            << "wrong token type - expected Scalar found " << t.info()
+            << "wrong token type - expected Scalar, found " << t.info()
             << exit(FatalIOError);
 
         return is;
diff --git a/src/OpenFOAM/primitives/bools/Switch/SwitchIO.C b/src/OpenFOAM/primitives/bools/Switch/SwitchIO.C
index d1c43ee858..81757e8952 100644
--- a/src/OpenFOAM/primitives/bools/Switch/SwitchIO.C
+++ b/src/OpenFOAM/primitives/bools/Switch/SwitchIO.C
@@ -74,7 +74,7 @@ Foam::Istream& Foam::operator>>(Istream& is, Switch& s)
     {
         is.setBad();
         FatalIOErrorIn("operator>>(Istream&, bool/Switch&)", is)
-            << "wrong token type - expected bool found " << t
+            << "wrong token type - expected bool, found " << t
             << exit(FatalIOError);
 
         return is;
diff --git a/src/OpenFOAM/primitives/ints/int/intIO.C b/src/OpenFOAM/primitives/ints/int/intIO.C
index b7a70228c0..17f4d1a1f6 100644
--- a/src/OpenFOAM/primitives/ints/int/intIO.C
+++ b/src/OpenFOAM/primitives/ints/int/intIO.C
@@ -67,7 +67,7 @@ Foam::Istream& Foam::operator>>(Istream& is, int& i)
     {
         is.setBad();
         FatalIOErrorIn("operator>>(Istream&, int&)", is)
-            << "wrong token type - expected int found " << t.info()
+            << "wrong token type - expected int, found " << t.info()
             << exit(FatalIOError);
 
         return is;
diff --git a/src/OpenFOAM/primitives/ints/long/longIO.C b/src/OpenFOAM/primitives/ints/long/longIO.C
index 2b7320164d..7ea56d0e2e 100644
--- a/src/OpenFOAM/primitives/ints/long/longIO.C
+++ b/src/OpenFOAM/primitives/ints/long/longIO.C
@@ -65,7 +65,7 @@ Foam::Istream& Foam::operator>>(Istream& is, long& l)
     {
         is.setBad();
         FatalIOErrorIn("operator>>(Istream&, long&)", is)
-            << "wrong token type - expected long found " << t.info()
+            << "wrong token type - expected long, found " << t.info()
             << exit(FatalIOError);
 
         return is;
diff --git a/src/OpenFOAM/primitives/ints/uint/uintIO.C b/src/OpenFOAM/primitives/ints/uint/uintIO.C
index 1d24188c91..7388266f4f 100644
--- a/src/OpenFOAM/primitives/ints/uint/uintIO.C
+++ b/src/OpenFOAM/primitives/ints/uint/uintIO.C
@@ -66,7 +66,7 @@ Foam::Istream& Foam::operator>>(Istream& is, unsigned int& i)
     {
         is.setBad();
         FatalIOErrorIn("operator>>(Istream&, unsigned int&)", is)
-            << "wrong token type - expected unsigned int found " << t.info()
+            << "wrong token type - expected unsigned int, found " << t.info()
             << exit(FatalIOError);
 
         return is;
diff --git a/src/OpenFOAM/primitives/ints/ulong/ulongIO.C b/src/OpenFOAM/primitives/ints/ulong/ulongIO.C
index 58d6900e11..63db00c1a1 100644
--- a/src/OpenFOAM/primitives/ints/ulong/ulongIO.C
+++ b/src/OpenFOAM/primitives/ints/ulong/ulongIO.C
@@ -63,7 +63,7 @@ Foam::Istream& Foam::operator>>(Istream& is, unsigned long& val)
     {
         is.setBad();
         FatalIOErrorIn("operator>>(Istream&, unsigned long&)", is)
-            << "wrong token type - expected unsigned long found " << t.info()
+            << "wrong token type - expected unsigned long, found " << t.info()
             << exit(FatalIOError);
 
         return is;
diff --git a/src/OpenFOAM/primitives/strings/keyType/keyTypeIO.C b/src/OpenFOAM/primitives/strings/keyType/keyTypeIO.C
index 72859abfc8..0e2f1d1133 100644
--- a/src/OpenFOAM/primitives/strings/keyType/keyTypeIO.C
+++ b/src/OpenFOAM/primitives/strings/keyType/keyTypeIO.C
@@ -58,12 +58,22 @@ Foam::Istream& Foam::operator>>(Istream& is, keyType& w)
     {
         // Assign from string. Sets regular expression.
         w = t.stringToken();
+
+        // flag empty strings as an error
+        if (w.empty())
+        {
+            is.setBad();
+            FatalIOErrorIn("operator>>(Istream&, keyType&)", is)
+                << "empty word/expression "
+                << exit(FatalIOError);
+            return is;
+        }
     }
     else
     {
         is.setBad();
         FatalIOErrorIn("operator>>(Istream&, keyType&)", is)
-            << "wrong token type - expected word or string found "
+            << "wrong token type - expected word or string, found "
             << t.info()
             << exit(FatalIOError);
 
diff --git a/src/OpenFOAM/primitives/strings/string/stringIO.C b/src/OpenFOAM/primitives/strings/string/stringIO.C
index 89694173ae..6cb4791b4a 100644
--- a/src/OpenFOAM/primitives/strings/string/stringIO.C
+++ b/src/OpenFOAM/primitives/strings/string/stringIO.C
@@ -55,7 +55,7 @@ Foam::Istream& Foam::operator>>(Istream& is, string& s)
     {
         is.setBad();
         FatalIOErrorIn("operator>>(Istream&, string&)", is)
-            << "wrong token type - expected string found " << t.info()
+            << "wrong token type - expected string, found " << t.info()
             << exit(FatalIOError);
 
         return is;
diff --git a/src/OpenFOAM/primitives/strings/word/wordIO.C b/src/OpenFOAM/primitives/strings/word/wordIO.C
index 093a282846..20a2a216d1 100644
--- a/src/OpenFOAM/primitives/strings/word/wordIO.C
+++ b/src/OpenFOAM/primitives/strings/word/wordIO.C
@@ -65,7 +65,8 @@ Foam::Istream& Foam::operator>>(Istream& is, word& w)
         {
             is.setBad();
             FatalIOErrorIn("operator>>(Istream&, word&)", is)
-                << "wrong token type - expected word found non-word characters "
+                << "wrong token type - expected word, found "
+                "non-word characters "
                 << t.info()
                 << exit(FatalIOError);
             return is;
@@ -75,7 +76,7 @@ Foam::Istream& Foam::operator>>(Istream& is, word& w)
     {
         is.setBad();
         FatalIOErrorIn("operator>>(Istream&, word&)", is)
-            << "wrong token type - expected word found "
+            << "wrong token type - expected word, found "
             << t.info()
             << exit(FatalIOError);
 
diff --git a/src/OpenFOAM/primitives/strings/wordRe/wordReIO.C b/src/OpenFOAM/primitives/strings/wordRe/wordReIO.C
index dab1542b27..c849b4237d 100644
--- a/src/OpenFOAM/primitives/strings/wordRe/wordReIO.C
+++ b/src/OpenFOAM/primitives/strings/wordRe/wordReIO.C
@@ -57,12 +57,22 @@ Foam::Istream& Foam::operator>>(Istream& is, wordRe& w)
     {
         // Auto-tests for regular expression
         w = t.stringToken();
+
+        // flag empty strings as an error
+        if (w.empty())
+        {
+            is.setBad();
+            FatalIOErrorIn("operator>>(Istream&, wordRe&)", is)
+                << "empty word/expression "
+                << exit(FatalIOError);
+            return is;
+        }
     }
     else
     {
         is.setBad();
         FatalIOErrorIn("operator>>(Istream&, wordRe&)", is)
-            << "wrong token type - expected word or string found "
+            << "wrong token type - expected word or string, found "
             << t.info()
             << exit(FatalIOError);