diff --git a/src/blackcore/airspacemonitor.cpp b/src/blackcore/airspacemonitor.cpp
index 4e49c8948..0c80a90fe 100644
--- a/src/blackcore/airspacemonitor.cpp
+++ b/src/blackcore/airspacemonitor.cpp
@@ -1148,16 +1148,25 @@ namespace BlackCore
         if (!simAircraft.isPartsSynchronized() && !isFull) { return; }
 
         CAircraftParts parts;
-        if (isFull)
+        try
         {
-            parts.convertFromJson(jsonObject);
+            if (isFull)
+            {
+                parts.convertFromJson(jsonObject);
+            }
+            else
+            {
+                // incremental update
+                parts = this->remoteAircraftParts(callsign).frontOrDefault();
+                QJsonObject config = applyIncrementalObject(parts.toJson(), jsonObject);
+                parts.convertFromJson(config);
+            }
         }
-        else
+        catch (const CJsonException &ex)
         {
-            // incremental update
-            parts = this->remoteAircraftParts(callsign).frontOrDefault();
-            QJsonObject config = applyIncrementalObject(parts.toJson(), jsonObject);
-            parts.convertFromJson(config);
+            CStatusMessage message = ex.toStatusMessage(this, "Invalid parts packet");
+            message.setSeverity(CStatusMessage::SeverityDebug);
+            CLogMessage::preformatted(message);
         }
 
         // make sure in any case right time
diff --git a/src/blackcore/application.cpp b/src/blackcore/application.cpp
index 297c3f3f5..982a0b946 100644
--- a/src/blackcore/application.cpp
+++ b/src/blackcore/application.cpp
@@ -175,7 +175,7 @@ namespace BlackCore
     CApplicationInfoList CApplication::getRunningApplications()
     {
         CApplicationInfoList apps;
-        apps.convertFromJson(CFileUtils::readLockedFileToString(swiftDataRoot() + "apps.json"));
+        apps.convertFromJsonNoThrow(CFileUtils::readLockedFileToString(swiftDataRoot() + "apps.json"), {}, {});
         apps.removeIf([](const CApplicationInfo &info) { return !info.processInfo().exists(); });
         return apps;
     }
diff --git a/src/blackgui/components/flightplancomponent.cpp b/src/blackgui/components/flightplancomponent.cpp
index b90e6ee69..23ecb7140 100644
--- a/src/blackgui/components/flightplancomponent.cpp
+++ b/src/blackgui/components/flightplancomponent.cpp
@@ -413,7 +413,15 @@ namespace BlackGui
                 }
 
                 CFlightPlan fp;
-                fp.convertFromJson(json);
+                try
+                {
+                    fp.convertFromJson(json);
+                }
+                catch (const CJsonException &ex)
+                {
+                    m = ex.toStatusMessage(this, "Parse error in " + fileName);
+                    break;
+                }
                 this->fillWithFlightPlanData(fp);
             }
             while (false);
diff --git a/src/blackgui/components/internalscomponent.cpp b/src/blackgui/components/internalscomponent.cpp
index 938c32842..d983ecc39 100644
--- a/src/blackgui/components/internalscomponent.cpp
+++ b/src/blackgui/components/internalscomponent.cpp
@@ -124,7 +124,16 @@ namespace BlackGui
                     CLogMessage(this).validationError("Parse error: %1") << jsonError.errorString();
                     return;
                 }
-                parts.convertFromJson(jsonDoc.object());
+
+                try
+                {
+                    parts.convertFromJson(jsonDoc.object());
+                }
+                catch (const CJsonException &ex)
+                {
+                    ex.toLogMessage(this, "Parse error");
+                    return;
+                }
                 partsToGui(parts);
             }
             else
diff --git a/src/blackgui/guiutility.cpp b/src/blackgui/guiutility.cpp
index 6e23ad30b..92ed03282 100644
--- a/src/blackgui/guiutility.cpp
+++ b/src/blackgui/guiutility.cpp
@@ -149,7 +149,8 @@ namespace BlackGui
         if (typeName.isEmpty() || typeId == QMetaType::UnknownType) { return CVariant(); }
 
         CVariant valueVariant;
-        valueVariant.convertFromJson(jsonObj);
+        const CStatusMessage status = valueVariant.convertFromJsonNoThrow(jsonObj, {}, {});
+        if (status.isFailure()) { return CVariant(); }
         return valueVariant;
     }
 
diff --git a/src/blackmisc/datacache.cpp b/src/blackmisc/datacache.cpp
index 24df4569b..34bd3220f 100644
--- a/src/blackmisc/datacache.cpp
+++ b/src/blackmisc/datacache.cpp
@@ -763,7 +763,7 @@ namespace BlackMisc
         auto json = QJsonDocument::fromJson(file.readAll()).object();
         QUuid uuid(json.value("uuid").toString());
         CSequence<CProcessInfo> apps;
-        apps.convertFromJson(json.value("apps").toObject());
+        auto status = apps.convertFromJsonNoThrow(json.value("apps").toObject(), this, QStringLiteral("Error in %1 apps object").arg(m_filename));
         apps.removeIf([](const CProcessInfo &pi) { return ! pi.exists(); });
 
         if (apps.isEmpty()) { uuid = CIdentifier().toUuid(); }
diff --git a/src/blackmisc/valuecache.cpp b/src/blackmisc/valuecache.cpp
index 25ee24595..fc3c99da2 100644
--- a/src/blackmisc/valuecache.cpp
+++ b/src/blackmisc/valuecache.cpp
@@ -329,7 +329,15 @@ namespace BlackMisc
     {
         CVariantMap map;
         map.convertFromMemoizedJson(json);
-        insertValues({ map, QDateTime::currentMSecsSinceEpoch() });
+        if (! map.isEmpty()) { insertValues({ map, QDateTime::currentMSecsSinceEpoch() }); }
+    }
+
+    CStatusMessageList CValueCache::loadFromJsonNoThrow(const QJsonObject &json, const CLogCategoryList &categories, const QString &prefix)
+    {
+        CVariantMap map;
+        auto messages = map.convertFromMemoizedJsonNoThrow(json, categories, prefix);
+        if (! map.isEmpty()) { insertValues({ map, QDateTime::currentMSecsSinceEpoch() }); }
+        return messages;
     }
 
     CStatusMessage CValueCache::saveToFiles(const QString &dir, const QString &keyPrefix)
@@ -418,6 +426,7 @@ namespace BlackMisc
                 keysInFiles.insert(filename.completeBaseName(), {});
             }
         }
+        bool ok = true;
         for (auto it = keysInFiles.cbegin(); it != keysInFiles.cend(); ++it)
         {
             QFile file(dir + "/" + it.key() + ".json");
@@ -435,13 +444,19 @@ namespace BlackMisc
                 return CStatusMessage(this).error("Invalid JSON format in %1") << file.fileName();
             }
             CVariantMap temp;
-            temp.convertFromMemoizedJson(json.object(), it.value());
-            if (it.value().isEmpty()) { temp.convertFromMemoizedJson(json.object()); }
+            const QString messagePrefix = QStringLiteral("Parsing %1.json").arg(it.key());
+            auto messages = temp.convertFromMemoizedJsonNoThrow(json.object(), it.value(), this, messagePrefix);
+            if (it.value().isEmpty()) { messages.push_back(temp.convertFromMemoizedJsonNoThrow(json.object(), this, messagePrefix)); }
+            if (! messages.isEmpty())
+            {
+                ok = false;
+                CLogMessage::preformatted(messages);
+            }
             temp.removeDuplicates(currentValues);
             o_values.insert(temp, QFileInfo(file).lastModified().toMSecsSinceEpoch());
         }
-        return CStatusMessage(this).info("Loaded cache values %1 from %2") <<
-            (keysMessage.isEmpty() ? o_values.keys().to<QStringList>().join(",") : keysMessage) << dir;
+        return CStatusMessage(this).info("Loaded cache values %1 from %2 %3") <<
+            (keysMessage.isEmpty() ? o_values.keys().to<QStringList>().join(",") : keysMessage) << dir << (ok ? "successfully" : "with errors");
     }
 
     void CValueCache::markAllAsSaved(const QString &keyPrefix)
diff --git a/src/blackmisc/valuecache.h b/src/blackmisc/valuecache.h
index 7db7140be..12c3f3755 100644
--- a/src/blackmisc/valuecache.h
+++ b/src/blackmisc/valuecache.h
@@ -21,7 +21,7 @@
 #include "blackmisc/propertyindex.h"
 #include "blackmisc/range.h"
 #include "blackmisc/slot.h"
-#include "blackmisc/statusmessage.h"
+#include "blackmisc/statusmessagelist.h"
 #include "blackmisc/valuecacheprivate.h"
 #include "blackmisc/variant.h"
 #include "blackmisc/variantmap.h"
@@ -193,9 +193,14 @@ namespace BlackMisc
 
         //! Load all values in Json format.
         //! Values already in the cache will remain in the cache unless they are overwritten.
+        //! \throws BlackMisc::CJsonException if JSON schema validation fails.
         //! \threadsafe
         void loadFromJson(const QJsonObject &json);
 
+        //! Call loadFromJson, catch any CJsonException that are thrown and return them as CStatusMessage.
+        //! \threadsafe
+        CStatusMessageList loadFromJsonNoThrow(const QJsonObject &json, const CLogCategoryList &categories, const QString &prefix);
+
         //! Save values to Json files in a given directory.
         //! If prefix is provided then only those values whose keys start with that prefix.
         //! \threadsafe