diff --git a/src/GWallet.Backend.Tests/MetaMarshalling.fs b/src/GWallet.Backend.Tests/MetaMarshalling.fs
index 57b26a353..eb60590b8 100644
--- a/src/GWallet.Backend.Tests/MetaMarshalling.fs
+++ b/src/GWallet.Backend.Tests/MetaMarshalling.fs
@@ -13,8 +13,11 @@ type MetaMarshalling() =
         Assert.That(json, Is.Not.Null)
         Assert.That(json, Is.Not.Empty)
 
-        let wrapperTypeString = Marshalling.ExtractStringType json
-        Assert.That(wrapperTypeString, Is.Not.Null)
-        Assert.That(wrapperTypeString, Is.Not.Empty)
+        let wrapper = Marshalling.ExtractWrapper json
+        Assert.That(wrapper, Is.Not.Null)
+        Assert.That(wrapper.TypeName, Is.Not.Null)
+        Assert.That(wrapper.TypeName, Is.Not.Empty)
+        Assert.That(wrapper.Version, Is.Not.Null)
+        Assert.That(wrapper.Version, Is.Not.Empty)
 
-        Assert.That(wrapperTypeString, Does.Not.Contain "Version=")
+        Assert.That(wrapper.TypeName, Does.Not.Contain "Version=")
diff --git a/src/GWallet.Backend/Marshalling.fs b/src/GWallet.Backend/Marshalling.fs
index 4f0cd0ab4..ca8e3aced 100644
--- a/src/GWallet.Backend/Marshalling.fs
+++ b/src/GWallet.Backend/Marshalling.fs
@@ -145,21 +145,46 @@ module Marshalling =
 
     let private currentVersion = VersionHelper.CURRENT_VERSION
 
-    let ExtractStringType(json: string): string =
+    let ExtractWrapper(json: string): MarshallingWrapper<obj> =
         if String.IsNullOrEmpty json then
             raise <| ArgumentNullException "json"
         let wrapper = JsonConvert.DeserializeObject<MarshallingWrapper<obj>> json
         if Object.ReferenceEquals(wrapper, null) then
             failwith <| SPrintF1 "Failed to extract type from JSON (null check): %s" json
-        wrapper.TypeName
+        if String.IsNullOrEmpty wrapper.TypeName then
+            failwith <| SPrintF1 "Failed to extract type from JSON (inner null check 1): %s" json
+        if String.IsNullOrEmpty wrapper.Version then
+            failwith <| SPrintF1 "Failed to extract type from JSON (inner null check 2): %s" json
+        wrapper
 
     let ExtractType(json: string): Type =
-        let typeName = ExtractStringType json
-        try
-            Type.GetType typeName
-        with
-        | :? NullReferenceException as _nre ->
-            failwith <| SPrintF1 "Failed to extract type from JSON (NRE): %s" json
+        let wrapper = ExtractWrapper json
+
+        let res =
+            try
+                // we prefer an ex with innerException than an NRE caused by the
+                // consumer of this function
+                let throwOnError = true
+
+                Type.GetType(wrapper.TypeName, throwOnError)
+            with
+            | :? NullReferenceException as _nre ->
+                failwith
+                <| SPrintF1 "Failed to extract type from JSON (NRE): %s" json
+            | ex ->
+                let errMsg =
+                    SPrintF2 "Problem when trying to find type '%s' (version '%s')"
+                        wrapper.TypeName
+                        wrapper.Version
+                raise <| Exception(errMsg, ex)
+        if isNull res then
+            failwith
+            <| SPrintF2
+                    "Could not find type '%s' (version '%s')"
+                    wrapper.TypeName
+                    wrapper.Version
+        res
+
 
     // FIXME: should we rather use JContainer.Parse? it seems JObject.Parse wouldn't detect error in this: {A:{"B": 1}}
     //        (for more info see replies of https://stackoverflow.com/questions/6903477/need-a-string-json-validator )