To attach a file to a post, you need to be using the main 'Post Reply' or 'New Topic' page and not 'Quick Reply', or Click the 'Attach' button to on an existing Message.
On this page, below the message box, you will find a check-box 'Attach files to this post?'. When you Click on the 'Post' button you are redirected to the Attachments Page where you can Upload and Attach Files.
To upload a file from your computer, click the 'Browse' button and locate the file. Once you have selected a file, click 'Upload'.
Once the upload is completed the file name will appear over the Upload Section. You can click 'Back' to return to the Topic.
1949 Belgian Standard
1955 UK RHD De Luxe