diff --git a/source/glest_game/type_instances/faction.cpp b/source/glest_game/type_instances/faction.cpp
index dc560443..3af11949 100644
--- a/source/glest_game/type_instances/faction.cpp
+++ b/source/glest_game/type_instances/faction.cpp
@@ -665,12 +665,14 @@ bool Faction::applyCosts(const ProducibleType *p){
         if(r == NULL) {
         	char szBuf[1024]="";
         	sprintf(szBuf,"cannot apply costs for p [%s] %d of %d costs resource is null",p->getName().c_str(),i,p->getCostCount());
+        	throw runtime_error(szBuf);
         }
 
         const ResourceType *rt= r->getType();
         if(rt == NULL) {
         	char szBuf[1024]="";
         	sprintf(szBuf,"cannot apply costs for p [%s] %d of %d costs resourcetype [%s] is null",p->getName().c_str(),i,p->getCostCount(),r->getDescription().c_str());
+        	throw runtime_error(szBuf);
         }
 		int cost= r->getAmount();
 		if((cost > 0 || (rt->getClass() != rcStatic)) && rt->getClass() != rcConsumable)
diff --git a/source/glest_game/types/unit_type.cpp b/source/glest_game/types/unit_type.cpp
index 43cdac05..8659e800 100644
--- a/source/glest_game/types/unit_type.cpp
+++ b/source/glest_game/types/unit_type.cpp
@@ -347,31 +347,52 @@ void UnitType::load(int id,const string &dir, const TechTree *techTree,
 		std::map<string,int> sortedItems;
 
 		//unit requirements
+		bool hasDup = false;
 		const XmlNode *unitRequirementsNode= parametersNode->getChild("unit-requirements");
 		for(int i=0; i<unitRequirementsNode->getChildCount(); ++i){
 			const XmlNode *unitNode= 	unitRequirementsNode->getChild("unit", i);
 			string name= unitNode->getAttribute("name")->getRestrictedValue();
+
+			if(sortedItems.find(name) != sortedItems.end()) {
+				hasDup = true;
+			}
+
 			sortedItems[name] = 0;
 		}
+		if(hasDup) {
+			printf("WARNING, unit type [%s] has one or more duplicate unit requirements\n",this->getName().c_str());
+		}
+
 		for(std::map<string,int>::iterator iterMap = sortedItems.begin();
 				iterMap != sortedItems.end(); ++iterMap) {
 			unitReqs.push_back(factionType->getUnitType(iterMap->first));
 		}
 		sortedItems.clear();
-
+		hasDup = false;
 
 		//upgrade requirements
 		const XmlNode *upgradeRequirementsNode= parametersNode->getChild("upgrade-requirements");
 		for(int i=0; i<upgradeRequirementsNode->getChildCount(); ++i){
 			const XmlNode *upgradeReqNode= upgradeRequirementsNode->getChild("upgrade", i);
 			string name= upgradeReqNode->getAttribute("name")->getRestrictedValue();
+
+			if(sortedItems.find(name) != sortedItems.end()) {
+				hasDup = true;
+			}
+
 			sortedItems[name] = 0;
 		}
+
+		if(hasDup) {
+			printf("WARNING, unit type [%s] has one or more duplicate upgrade requirements\n",this->getName().c_str());
+		}
+
 		for(std::map<string,int>::iterator iterMap = sortedItems.begin();
 				iterMap != sortedItems.end(); ++iterMap) {
 			upgradeReqs.push_back(factionType->getUpgradeType(iterMap->first));
 		}
 		sortedItems.clear();
+		hasDup = false;
 
 		//resource requirements
 		const XmlNode *resourceRequirementsNode= parametersNode->getChild("resource-requirements");
@@ -380,8 +401,18 @@ void UnitType::load(int id,const string &dir, const TechTree *techTree,
 			const XmlNode *resourceNode= resourceRequirementsNode->getChild("resource", i);
 			string name= resourceNode->getAttribute("name")->getRestrictedValue();
 			int amount= resourceNode->getAttribute("amount")->getIntValue();
+
+			if(sortedItems.find(name) != sortedItems.end()) {
+				hasDup = true;
+			}
 			sortedItems[name] = amount;
 		}
+		//if(hasDup || sortedItems.size() != costs.size()) printf("Found duplicate resource requirement, costs.size() = %d sortedItems.size() = %d\n",costs.size(),sortedItems.size());
+
+		if(hasDup) {
+			printf("WARNING, unit type [%s] has one or more duplicate resource requirements\n",this->getName().c_str());
+		}
+
 		if(sortedItems.size() < costs.size()) {
 			costs.resize(sortedItems.size());
 		}
@@ -392,6 +423,7 @@ void UnitType::load(int id,const string &dir, const TechTree *techTree,
 			index++;
 		}
 		sortedItems.clear();
+		hasDup = false;
 
 		//resources stored
 		const XmlNode *resourcesStoredNode= parametersNode->getChild("resources-stored");
@@ -400,8 +432,18 @@ void UnitType::load(int id,const string &dir, const TechTree *techTree,
 			const XmlNode *resourceNode= resourcesStoredNode->getChild("resource", i);
 			string name= resourceNode->getAttribute("name")->getRestrictedValue();
 			int amount= resourceNode->getAttribute("amount")->getIntValue();
+
+			if(sortedItems.find(name) != sortedItems.end()) {
+				hasDup = true;
+			}
+
 			sortedItems[name] = amount;
 		}
+
+		if(hasDup) {
+			printf("WARNING, unit type [%s] has one or more duplicate stored resources\n",this->getName().c_str());
+		}
+
 		if(sortedItems.size() < storedResources.size()) {
 			storedResources.resize(sortedItems.size());
 		}
diff --git a/source/glest_game/types/upgrade_type.cpp b/source/glest_game/types/upgrade_type.cpp
index 08dc0c6d..dd5f2f11 100644
--- a/source/glest_game/types/upgrade_type.cpp
+++ b/source/glest_game/types/upgrade_type.cpp
@@ -258,41 +258,81 @@ void UpgradeType::load(const string &dir, const TechTree *techTree,
 		std::map<string,int> sortedItems;
 
 		//unit requirements
+		bool hasDup = false;
 		const XmlNode *unitRequirementsNode= upgradeNode->getChild("unit-requirements");
 		for(int i = 0; i < unitRequirementsNode->getChildCount(); ++i) {
 			const XmlNode *unitNode= 	unitRequirementsNode->getChild("unit", i);
 			string name= unitNode->getAttribute("name")->getRestrictedValue();
+
+			if(sortedItems.find(name) != sortedItems.end()) {
+				hasDup = true;
+			}
+
 			sortedItems[name] = 0;
 		}
+
+		if(hasDup) {
+			printf("WARNING, upgrade type [%s] has one or more duplicate unit requirements\n",this->getName().c_str());
+		}
+
 		for(std::map<string,int>::iterator iterMap = sortedItems.begin();
 				iterMap != sortedItems.end(); ++iterMap) {
 			unitReqs.push_back(factionType->getUnitType(iterMap->first));
 		}
 		sortedItems.clear();
+		hasDup = false;
 
 		//upgrade requirements
 		const XmlNode *upgradeRequirementsNode= upgradeNode->getChild("upgrade-requirements");
 		for(int i = 0; i < upgradeRequirementsNode->getChildCount(); ++i) {
 			const XmlNode *upgradeReqNode= upgradeRequirementsNode->getChild("upgrade", i);
 			string name= upgradeReqNode->getAttribute("name")->getRestrictedValue();
+
+			if(sortedItems.find(name) != sortedItems.end()) {
+				hasDup = true;
+			}
+
 			sortedItems[name] = 0;
 		}
+
+		if(hasDup) {
+			printf("WARNING, upgrade type [%s] has one or more duplicate upgrade requirements\n",this->getName().c_str());
+		}
+
 		for(std::map<string,int>::iterator iterMap = sortedItems.begin();
 				iterMap != sortedItems.end(); ++iterMap) {
 			upgradeReqs.push_back(factionType->getUpgradeType(iterMap->first));
 		}
 		sortedItems.clear();
+		hasDup = false;
 
 		//resource requirements
 		int index = 0;
 		const XmlNode *resourceRequirementsNode= upgradeNode->getChild("resource-requirements");
+		hasDup = false;
 		costs.resize(resourceRequirementsNode->getChildCount());
 		for(int i = 0; i < costs.size(); ++i) {
 			const XmlNode *resourceNode= 	resourceRequirementsNode->getChild("resource", i);
 			string name= resourceNode->getAttribute("name")->getRestrictedValue();
 			int amount= resourceNode->getAttribute("amount")->getIntValue();
+
+			if(sortedItems.find(name) != sortedItems.end()) {
+				hasDup = true;
+			}
+
 			sortedItems[name] = amount;
 		}
+
+		//if(hasDup || sortedItems.size() != costs.size()) printf("Found duplicate resource requirement, costs.size() = %d sortedItems.size() = %d\n",costs.size(),sortedItems.size());
+
+		if(hasDup) {
+			printf("WARNING, upgrade type [%s] has one or more duplicate resource requirements\n",this->getName().c_str());
+		}
+
+		if(sortedItems.size() < costs.size()) {
+			costs.resize(sortedItems.size());
+		}
+
 		index = 0;
 		for(std::map<string,int>::iterator iterMap = sortedItems.begin();
 				iterMap != sortedItems.end(); ++iterMap) {
@@ -300,14 +340,25 @@ void UpgradeType::load(const string &dir, const TechTree *techTree,
 			index++;
 		}
 		sortedItems.clear();
+		hasDup = false;
 
 		//effects
 		const XmlNode *effectsNode= upgradeNode->getChild("effects");
 		for(int i = 0; i < effectsNode->getChildCount(); ++i) {
 			const XmlNode *unitNode= effectsNode->getChild("unit", i);
 			string name= unitNode->getAttribute("name")->getRestrictedValue();
+
+			if(sortedItems.find(name) != sortedItems.end()) {
+				hasDup = true;
+			}
+
 			sortedItems[name] = 0;
 		}
+
+		if(hasDup) {
+			printf("WARNING, upgrade type [%s] has one or more duplicate effects\n",this->getName().c_str());
+		}
+
 		for(std::map<string,int>::iterator iterMap = sortedItems.begin();
 				iterMap != sortedItems.end(); ++iterMap) {
 			effects.push_back(factionType->getUnitType(iterMap->first));