diff --git a/sdk/scannerlib/HGLibDeviceImpl.cpp b/sdk/scannerlib/HGLibDeviceImpl.cpp
index c079c3ca..4d421c7c 100644
--- a/sdk/scannerlib/HGLibDeviceImpl.cpp
+++ b/sdk/scannerlib/HGLibDeviceImpl.cpp
@@ -560,18 +560,19 @@ HGLibDeviceParamGroup* HGLibDeviceImpl::GetParamGroupList(HGUInt* count)
 			devParam.valueType = HGLIB_OPTION_VALUETYPE_ENUM;
 			devParam.stringValue = value;
 
-			assert(SANE_CONSTRAINT_STRING_LIST == desp->constraint_type);
+            devParam.rangeType = HGLIB_OPTION_VALUERANGETYPE_ENUMLIST;
+            if (SANE_CONSTRAINT_STRING_LIST == desp->constraint_type)
+            {
+                const SANE_String_Const* p = desp->constraint.string_list;
+                while (NULL != *p)
+                {
+                    devParam.stringValueList.push_back(*p);
+                    ++p;
+                }
 
-			devParam.rangeType = HGLIB_OPTION_VALUERANGETYPE_ENUMLIST;
-			const SANE_String_Const* p = desp->constraint.string_list;
-			while (NULL != *p)
-			{
-				devParam.stringValueList.push_back(*p);
-				++p;
-			}
-
-			assert(!devParams.empty());
-			devParams[devParams.size() - 1].devParams.push_back(devParam);
+                assert(!devParams.empty());
+                devParams[devParams.size() - 1].devParams.push_back(devParam);
+            }
 		}
 		else if (SANE_TYPE_INT == desp->type)
 		{
@@ -763,15 +764,16 @@ HGLibDeviceParam* HGLibDeviceImpl::GetParam(HGUInt option)
 				devParam.valueType = HGLIB_OPTION_VALUETYPE_ENUM;
 				devParam.stringValue = value;
 
-				assert(SANE_CONSTRAINT_STRING_LIST == desp->constraint_type);
-
-				devParam.rangeType = HGLIB_OPTION_VALUERANGETYPE_ENUMLIST;
-				const SANE_String_Const* p = desp->constraint.string_list;
-				while (NULL != *p)
-				{
-					devParam.stringValueList.push_back(*p);
-					++p;
-				}
+                devParam.rangeType = HGLIB_OPTION_VALUERANGETYPE_ENUMLIST;
+                if (SANE_CONSTRAINT_STRING_LIST == desp->constraint_type)
+                {
+                    const SANE_String_Const* p = desp->constraint.string_list;
+                    while (NULL != *p)
+                    {
+                        devParam.stringValueList.push_back(*p);
+                        ++p;
+                    }
+                }
 			}
 			else if (SANE_TYPE_INT == desp->type)
 			{
diff --git a/sdk/webservice/ManagerV2.cpp b/sdk/webservice/ManagerV2.cpp
index 684f5a2d..6932cdfe 100644
--- a/sdk/webservice/ManagerV2.cpp
+++ b/sdk/webservice/ManagerV2.cpp
@@ -3528,18 +3528,19 @@ namespace ver_2
 				devParam.valueType = 1;
 				devParam.stringValue = value;
 
-				assert(SANE_CONSTRAINT_STRING_LIST == desp->constraint_type);
+                devParam.rangeType = 1;
+                if (SANE_CONSTRAINT_STRING_LIST == desp->constraint_type)
+                {
+                    const SANE_String_Const* p = desp->constraint.string_list;
+                    while (NULL != *p)
+                    {
+                        devParam.stringValueList.push_back(*p);
+                        ++p;
+                    }
 
-				devParam.rangeType = 1;
-				const SANE_String_Const* p = desp->constraint.string_list;
-				while (NULL != *p)
-				{
-					devParam.stringValueList.push_back(*p);
-					++p;
-				}
-
-				assert(!devParams.empty());
-				devParams[devParams.size() - 1].devParams.push_back(devParam);
+                    assert(!devParams.empty());
+                    devParams[devParams.size() - 1].devParams.push_back(devParam);
+                }
 			}
 			else if (SANE_TYPE_INT == desp->type)
 			{