diff --git a/client/src/models/AssetModel.ts b/client/src/models/AssetModel.ts
index e250909..7538119 100644
--- a/client/src/models/AssetModel.ts
+++ b/client/src/models/AssetModel.ts
@@ -12,11 +12,11 @@ const AssetModel = {
         type: '',
         license: null,
         copyrightHolder: null,
-        workExample: null,
+        workExample: '',
         files: [],
         categories: [],
         links: [],
-        inLanguage: null,
+        inLanguage: '',
         tags: [],
         price: ''
     },
diff --git a/client/src/routes/Publish/index.tsx b/client/src/routes/Publish/index.tsx
index 0f9b655..54c9ff6 100644
--- a/client/src/routes/Publish/index.tsx
+++ b/client/src/routes/Publish/index.tsx
@@ -273,7 +273,10 @@ export default class Publish extends Component<{}, PublishState> {
             base: Object.assign(AssetModel.base, {
                 name: this.state.name,
                 description: this.state.description,
-                dateCreated: new Date(this.state.dateCreated).toISOString(),
+                dateCreated:
+                    new Date(this.state.dateCreated)
+                        .toISOString()
+                        .split('.')[0] + 'Z', // remove milliseconds
                 author: this.state.author,
                 license: this.state.license,
                 copyrightHolder: this.state.copyrightHolder,
diff --git a/server/src/routes/UrlCheckRouter.ts b/server/src/routes/UrlCheckRouter.ts
index 09eccae..dbe6eff 100644
--- a/server/src/routes/UrlCheckRouter.ts
+++ b/server/src/routes/UrlCheckRouter.ts
@@ -31,8 +31,9 @@ export class UrlCheckRouter {
                     result.found = true
 
                     if (response.headers['content-length']) {
-                        result.contentLength =
+                        result.contentLength = parseInt(
                             response.headers['content-length']
+                        ) // convert to number
                     }
 
                     if (response.headers['content-type']) {