diff --git a/FileManager/PersistentDictionary.cs b/FileManager/PersistentDictionary.cs
index 963b51a4..53e87c9a 100644
--- a/FileManager/PersistentDictionary.cs
+++ b/FileManager/PersistentDictionary.cs
@@ -208,7 +208,7 @@ namespace FileManager
             {
                 var msg = "Unrecoverable error. Settings file cannot be found";
                 var ex = new FileNotFoundException(msg, Filepath);
-                Serilog.Log.Logger.Error(msg, ex);
+                Serilog.Log.Logger.Error(ex, msg);
                 throw ex;
             }
 
@@ -226,7 +226,7 @@ namespace FileManager
             {
                 var msg = "Unrecoverable error. Unable to read settings from Settings file";
                 var ex = new NullReferenceException(msg);
-                Serilog.Log.Logger.Error(msg, ex);
+                Serilog.Log.Logger.Error(ex, msg);
                 throw ex;
             }
 
diff --git a/LibationFileManager/FilePathCache.cs b/LibationFileManager/FilePathCache.cs
index 43b75bbc..4359ef88 100644
--- a/LibationFileManager/FilePathCache.cs
+++ b/LibationFileManager/FilePathCache.cs
@@ -26,6 +26,18 @@ namespace LibationFileManager
 			if (File.Exists(jsonFile))
 			{
 				var list = JsonConvert.DeserializeObject<List<CacheEntry>>(File.ReadAllText(jsonFile));
+
+				// file exists but deser is null. this will never happen when file is healthy
+				if (list is null)
+				{
+					lock (locker)
+					{
+						Serilog.Log.Logger.Error("Error deserializing file. Wrong format. Possibly corrupt. Deleting file. {@DebugInfo}", new { jsonFile });
+						File.Delete(jsonFile);
+						return;
+					}
+				}
+
 				cache = new Cache<CacheEntry>(list);
 			}
         }