HTML code in the console when logging-in from a subwiki

Steps to reproduce:

1. Go to http://localhost:8080/xwiki/bin/view/WorkspaceManager/Install and install the Wiki template
2. Create a new subwiki: Add -> Wiki
3. Click "Log-Out"
4. Hover over XWiki and click on Wiki Directory
5. Click on the subwiki you previously created
6. Click "Log-In"
7. Type in your credentials and click "Log-In"

I've attached my stacktrace.