diff --git a/trick_source/codegen/Interface_Code_Gen/FieldDescription.cpp b/trick_source/codegen/Interface_Code_Gen/FieldDescription.cpp
index 5c37c6cb..359b9463 100644
--- a/trick_source/codegen/Interface_Code_Gen/FieldDescription.cpp
+++ b/trick_source/codegen/Interface_Code_Gen/FieldDescription.cpp
@@ -24,7 +24,7 @@ static ut_system * get_u_system() {
     /* Initialize the udunits-2 library */
     ut_set_error_message_handler(ut_ignore) ;
     if( (u_system = ut_read_xml( NULL )) == NULL ) {
-        std::cout << "Error initializing udunits-2 unit system" << std::endl ;
+        std::cerr << "Error initializing udunits-2 unit system" << std::endl ;
         exit(-1);
     }
     ut_set_error_message_handler(ut_write_to_stderr) ;
@@ -98,7 +98,7 @@ std::string FieldDescription::get_regex_field(std::string input , const char * e
     } else {
         //char error_msg[1024] ;
         //regerror( ret , &reg_expr , (char *)error_msg , 1024 ) ;
-        //std::cout << error_msg << std::endl ;
+        //std::cerr << error_msg << std::endl ;
     }
     return std::string() ;
 }
diff --git a/trick_source/codegen/Interface_Code_Gen/PrintAttributes.cpp b/trick_source/codegen/Interface_Code_Gen/PrintAttributes.cpp
index 501ca908..d1125c06 100644
--- a/trick_source/codegen/Interface_Code_Gen/PrintAttributes.cpp
+++ b/trick_source/codegen/Interface_Code_Gen/PrintAttributes.cpp
@@ -80,7 +80,7 @@ static void _mkdir(const char *dir) {
             if ( stat( tmp , &buf ) != 0 ) {
                 int returnValue = mkdir(tmp, S_IRWXU | S_IRWXG | S_IRWXO);
                 if (returnValue) {
-                    std::cout << bold(color(ERROR, "Error")) << "      Unable to create " << quote(bold(tmp)) << " for writing: " << strerror(errno) << std::endl;
+                    std::cerr << bold(color(ERROR, "Error")) << "      Unable to create " << quote(bold(tmp)) << " for writing: " << strerror(errno) << std::endl;
                     return ;
                 }
             }
@@ -89,7 +89,7 @@ static void _mkdir(const char *dir) {
     if ( stat( tmp , &buf ) != 0 ) {
         int returnValue = mkdir(tmp, S_IRWXU | S_IRWXG | S_IRWXO);
         if (returnValue) {
-            std::cout << bold(color(ERROR, "Error")) << "      Unable to create " << quote(bold(tmp)) << " for writing: " << strerror(errno) << std::endl;
+            std::cerr << bold(color(ERROR, "Error")) << "      Unable to create " << quote(bold(tmp)) << " for writing: " << strerror(errno) << std::endl;
             return ;
         }
     }
diff --git a/trick_source/data_products/Log/Csv.cpp b/trick_source/data_products/Log/Csv.cpp
index 155a994a..12dec266 100644
--- a/trick_source/data_products/Log/Csv.cpp
+++ b/trick_source/data_products/Log/Csv.cpp
@@ -18,7 +18,7 @@ Csv::Csv(char * file_name , char * param_name ) {
         len = strlen(param_name) ;
 
         if ((fp_ = fopen(file_name , "r")) == 0 ) {
-           std::cout << "ERROR:  Couldn't open \"" << file_name << "\": " << std::strerror(errno) << std::endl;
+           std::cerr << "ERROR:  Couldn't open \"" << file_name << "\": " << std::strerror(errno) << std::endl;
            exit(-1) ;
         }
 
@@ -175,7 +175,7 @@ int CsvLocateParam( char * file_name , char * param_name ) {
 
         }
         else {
-           std::cout << "ERROR:  Couldn't open \"" << file_name << "\": " << std::strerror(errno) << std::endl;
+           std::cerr << "ERROR:  Couldn't open \"" << file_name << "\": " << std::strerror(errno) << std::endl;
         }
 
         return(0) ;
diff --git a/trick_source/data_products/Log/MatLab.cpp b/trick_source/data_products/Log/MatLab.cpp
index ca4b132e..b222d9a7 100644
--- a/trick_source/data_products/Log/MatLab.cpp
+++ b/trick_source/data_products/Log/MatLab.cpp
@@ -74,7 +74,7 @@ MatLab::MatLab(char * file_name, char * param_name, char * time_name) {
     fileName_ = file_name;
 
     if ((fp_ = fopen(file_name, "r")) == 0) {
-        std::cout << "ERROR:  Couldn't open \"" << file_name << "\": " << std::strerror(errno) << std::endl;
+        std::cerr << "ERROR:  Couldn't open \"" << file_name << "\": " << std::strerror(errno) << std::endl;
         return;
     }
 
@@ -660,7 +660,7 @@ int MatLabLocateParam(char * file_name, char * param_name, char * time_name) {
     int field_index, field_num;
 
     if ((fp = fopen(file_name, "r")) == 0) {
-        std::cout << "ERROR:  Couldn't open \"" << file_name << "\": " << std::strerror(errno) << std::endl;
+        std::cerr << "ERROR:  Couldn't open \"" << file_name << "\": " << std::strerror(errno) << std::endl;
         return (0);
     }
 
diff --git a/trick_source/data_products/Log/MatLab4.cpp b/trick_source/data_products/Log/MatLab4.cpp
index d0f26063..b7900c23 100644
--- a/trick_source/data_products/Log/MatLab4.cpp
+++ b/trick_source/data_products/Log/MatLab4.cpp
@@ -33,7 +33,7 @@ MatLab4::MatLab4(char * file_name , char * param_name , char * time_name ) {
         TRICK_GET_BYTE_ORDER(my_byte_order) ;
 
         if ((fp_ = fopen(file_name , "r")) == 0 ) {
-           std::cout << "ERROR:  Couldn't open \"" << file_name << "\": " << std::strerror(errno) << std::endl;
+           std::cerr << "ERROR:  Couldn't open \"" << file_name << "\": " << std::strerror(errno) << std::endl;
            exit(-1) ;
         }
 
@@ -283,7 +283,7 @@ int MatLab4LocateParam( char *file_name , char *param_name , char *time_name ) {
         TRICK_GET_BYTE_ORDER(my_byte_order) ;
 
         if ((fp = fopen(file_name , "r")) == 0 ) {
-           std::cout << "ERROR:  Couldn't open \"" << file_name << "\": " << std::strerror(errno) << std::endl;
+           std::cerr << "ERROR:  Couldn't open \"" << file_name << "\": " << std::strerror(errno) << std::endl;
            exit(-1) ;
         }
 
diff --git a/trick_source/data_products/Log/TrickBinary.cpp b/trick_source/data_products/Log/TrickBinary.cpp
index b8fca687..0220d754 100644
--- a/trick_source/data_products/Log/TrickBinary.cpp
+++ b/trick_source/data_products/Log/TrickBinary.cpp
@@ -179,7 +179,7 @@ TrickBinary::TrickBinary(char * file_name , char * param_name ) {
                 record_ = new char[record_size_] ;
         }
         else {
-            std::cout << "ERROR:  Couldn't open \"" << file_name << "\": " << std::strerror(errno) << std::endl;
+            std::cerr << "ERROR:  Couldn't open \"" << file_name << "\": " << std::strerror(errno) << std::endl;
         }
 }
 
@@ -411,7 +411,7 @@ int TrickBinaryGetNumVariables(const char* file_name) {
                 fread(&num_params , 4 , 1 , fp ) ;
                 if ( swap ) { num_params = trick_byteswap_int(num_params) ; }
         } else {
-                std::cout << "ERROR:  Couldn't open \"" << file_name << "\": " << std::strerror(errno) << std::endl;
+                std::cerr << "ERROR:  Couldn't open \"" << file_name << "\": " << std::strerror(errno) << std::endl;
                 return(0) ;
         }
 
@@ -477,7 +477,7 @@ char** TrickBinaryGetVariableNames(const char* file_name) {
                  }
         }
         else {
-                std::cout << "ERROR:  Couldn't open \"" << file_name << "\": " << std::strerror(errno) << std::endl;
+                std::cerr << "ERROR:  Couldn't open \"" << file_name << "\": " << std::strerror(errno) << std::endl;
                 return(0) ;
         }
 
@@ -544,7 +544,7 @@ char** TrickBinaryGetVariableUnits(const char* file_name) {
                  }
         }
         else {
-                std::cout << "ERROR:  Couldn't open \"" << file_name << "\": " << std::strerror(errno) << std::endl;
+                std::cerr << "ERROR:  Couldn't open \"" << file_name << "\": " << std::strerror(errno) << std::endl;
                 return(0) ;
         }
 
diff --git a/trick_source/data_products/Log/TrickHDF5.cpp b/trick_source/data_products/Log/TrickHDF5.cpp
index 859ffed0..8fa585a5 100644
--- a/trick_source/data_products/Log/TrickHDF5.cpp
+++ b/trick_source/data_products/Log/TrickHDF5.cpp
@@ -21,7 +21,7 @@ TrickHDF5::TrickHDF5(char *file_name , char *parameter_name , char *time_name) {
      * Open the HDF5 file.
      */
     if ( (file = H5Fopen( file_name, H5F_ACC_RDONLY, H5P_DEFAULT )) < 0 ) {
-        cout << "ERROR:  Couldn't open file \"" << file_name << "\"" << endl;
+        cerr << "ERROR:  Couldn't open file \"" << file_name << "\"" << endl;
         exit(-1);
     }
 
@@ -31,7 +31,7 @@ TrickHDF5::TrickHDF5(char *file_name , char *parameter_name , char *time_name) {
      */
     root_group = H5Gopen( file, "/", H5P_DEFAULT );
     if ( root_group < 0 ) {
-        cout << "ERROR:  Couldn't open group \"" <<  "/" << "\"" << endl;
+        cerr << "ERROR:  Couldn't open group \"" <<  "/" << "\"" << endl;
         exit(-1);
     }
 
@@ -77,13 +77,13 @@ TrickHDF5::TrickHDF5(char *file_name , char *parameter_name , char *time_name) {
      */
     parameter_dataset = H5PTopen( root_group, parameter_name );
     if ( H5PTis_valid(parameter_dataset) < 0 ) {
-        cout << "ERROR:  Couldn't open packet table \""
+        cerr << "ERROR:  Couldn't open packet table \""
              << parameter_name << "\"" << endl;
         exit(-1);
     }
     time_dataset = H5PTopen( root_group, time_name );
     if ( H5PTis_valid(time_dataset) < 0 ) {
-        cout << "ERROR:  Couldn't open packet table \""
+        cerr << "ERROR:  Couldn't open packet table \""
              << time_name << "\"" << endl;
         exit(-1);
     }
@@ -185,14 +185,14 @@ int HDF5LocateParam( const char * file_name, const char * parameter_name ) {
     //! Open an existing HDF5 file and get a file identifier.
     hid_t file = H5Fopen(file_name, H5F_ACC_RDONLY, H5P_DEFAULT);
     if (file < 0) {
-        cout << "ERROR:  Couldn't open file \"" << file_name << "\"" << endl;
+        cerr << "ERROR:  Couldn't open file \"" << file_name << "\"" << endl;
         return 0;
     }
 
     //! Open group containing data.
     hid_t group = H5Gopen(file, "/", H5P_DEFAULT);
     if (group < 0) {
-        cout << "ERROR:  Couldn't open group \"" <<  "/" << "\"" << endl;
+        cerr << "ERROR:  Couldn't open group \"" <<  "/" << "\"" << endl;
         return 0;
     }
 
@@ -205,7 +205,7 @@ int HDF5LocateParam( const char * file_name, const char * parameter_name ) {
      */
     hid_t packet_table = H5PTopen(group, parameter_name);
     if ( H5PTis_valid(packet_table) < 0 ) {
-        cout << "ERROR:  Couldn't open packet table \""
+        cerr << "ERROR:  Couldn't open packet table \""
              << parameter_name << "\"" << endl;
         return 0;
     }
diff --git a/trick_source/data_products/Log/log.cpp b/trick_source/data_products/Log/log.cpp
index 372edbe1..87cfba37 100644
--- a/trick_source/data_products/Log/log.cpp
+++ b/trick_source/data_products/Log/log.cpp
@@ -1021,7 +1021,7 @@ int LogData::setUnit(int paramIdx, std::string to_units)
             unitVal_[paramIdx] = cv_convert_double(converter, 1.0 ) - biasVal_[paramIdx] ;
             cv_free(converter) ;
         } else {
-            std::cout << "Units conversion error from " << from_units << " to " << to_units << std::endl ;
+            std::cerr << "Units conversion error from " << from_units << " to " << to_units << std::endl ;
             return -1 ;
         }
 
diff --git a/trick_source/sim_services/DataTypes/src/ArrayDataType.cpp b/trick_source/sim_services/DataTypes/src/ArrayDataType.cpp
index f23084af..2f21f2fd 100644
--- a/trick_source/sim_services/DataTypes/src/ArrayDataType.cpp
+++ b/trick_source/sim_services/DataTypes/src/ArrayDataType.cpp
@@ -204,7 +204,7 @@ void* ArrayDataType::createInstance(unsigned int num) const {
     if (subType != NULL) {
         return subType->createInstance( num * elementCount );
     } else {
-        std::cout << "ERROR: Can't create an instance of an unvalidated type." << std::endl;
+        std::cerr << "ERROR: Can't create an instance of an unvalidated type." << std::endl;
         return (void*) NULL;
     }
 }
diff --git a/trick_source/sim_services/DataTypes/src/CompositeDataType.cpp b/trick_source/sim_services/DataTypes/src/CompositeDataType.cpp
index ae7c2a2c..50a25c07 100644
--- a/trick_source/sim_services/DataTypes/src/CompositeDataType.cpp
+++ b/trick_source/sim_services/DataTypes/src/CompositeDataType.cpp
@@ -136,13 +136,13 @@ void* CompositeDataType::createInstance(unsigned int num) const {
     if (allocator == NULL) {
         // Allocate using calloc.
         if ((address = calloc( (size_t)num, (size_t)structSize ))  == NULL) {
-            std::cout << "ERROR: Out of memory." << std::endl;
+            std::cerr << "ERROR: Out of memory." << std::endl;
             return ((void*)NULL);
         }
     } else {
         // Allocate using the allocator.
         if ((address = allocator( num)) == NULL) {
-            std::cout << "ERROR: Out of memory." << std::endl;
+            std::cerr << "ERROR: Out of memory." << std::endl;
             return ((void*)NULL);
         }
     }
diff --git a/trick_source/sim_services/DataTypes/src/MemMgr.cpp b/trick_source/sim_services/DataTypes/src/MemMgr.cpp
index 8106aab4..63fe9e81 100644
--- a/trick_source/sim_services/DataTypes/src/MemMgr.cpp
+++ b/trick_source/sim_services/DataTypes/src/MemMgr.cpp
@@ -34,7 +34,7 @@ void* MemMgr::declare_var( const std::string& typeSpecifier,
                            void*              suppliedAllocation ) {
 
     if ( var_exists( variableName )) {
-        std::cout << "ERROR: Variable " << variableName << " already declared." << std::endl;
+        std::cerr << "ERROR: Variable " << variableName << " already declared." << std::endl;
         return ((void*)NULL);
     }
 
diff --git a/trick_source/sim_services/MemoryManager/MemoryManager_alloc_depends.cpp b/trick_source/sim_services/MemoryManager/MemoryManager_alloc_depends.cpp
index f53c7769..acb927aa 100644
--- a/trick_source/sim_services/MemoryManager/MemoryManager_alloc_depends.cpp
+++ b/trick_source/sim_services/MemoryManager/MemoryManager_alloc_depends.cpp
@@ -14,7 +14,7 @@ void Trick::MemoryManager::get_alloc_deps_in_allocation(ALLOC_INFO* alloc_info )
     }
 
     if (alloc_info == NULL) {
-        std::cout << "ERROR: Trick::MemoryManager::get_alloc_deps_in_allocation called with alloc_info == NULL." << std::endl;
+        std::cerr << "ERROR: Trick::MemoryManager::get_alloc_deps_in_allocation called with alloc_info == NULL." << std::endl;
         std::cout.flush();
         return;
     }
diff --git a/trick_source/sim_services/MemoryManager/MemoryManager_get_stl_dependencies.cpp b/trick_source/sim_services/MemoryManager/MemoryManager_get_stl_dependencies.cpp
index 3cfc3ce9..dbd3afe2 100644
--- a/trick_source/sim_services/MemoryManager/MemoryManager_get_stl_dependencies.cpp
+++ b/trick_source/sim_services/MemoryManager/MemoryManager_get_stl_dependencies.cpp
@@ -14,7 +14,7 @@ void Trick::MemoryManager::get_stl_dependencies( ALLOC_INFO* alloc_info ) {
     }
 
     if (alloc_info == NULL) {
-        std::cout << "ERROR: Trick::MemoryManager::get_stl_dependencies called with alloc_info == NULL." << std::endl;
+        std::cerr << "ERROR: Trick::MemoryManager::get_stl_dependencies called with alloc_info == NULL." << std::endl;
         std::cout.flush();
         return;
     }
diff --git a/trick_source/sim_services/MemoryManager/MemoryManager_restore_stls.cpp b/trick_source/sim_services/MemoryManager/MemoryManager_restore_stls.cpp
index 0aba1563..8148e7ab 100644
--- a/trick_source/sim_services/MemoryManager/MemoryManager_restore_stls.cpp
+++ b/trick_source/sim_services/MemoryManager/MemoryManager_restore_stls.cpp
@@ -14,7 +14,7 @@ void Trick::MemoryManager::restore_stls( ALLOC_INFO* alloc_info ) {
     }
 
     if (alloc_info == NULL) {
-        std::cout << "ERROR: Trick::MemoryManager::restore_stls called with alloc_info == NULL." << std::endl;
+        std::cerr << "ERROR: Trick::MemoryManager::restore_stls called with alloc_info == NULL." << std::endl;
         std::cout.flush();
         return;
     }