When web-form submissions fail

When you submit information from a form on any website, there are several ways in which the submission may fail. 

• Client-script errors (bugs with the web-page code) or functioning client-side validation code may prevent the submission from being sent.
• Network problems at any point between the user and the server may physically stop the submission from being transmitted. 
• Server-side software errors, hardware problems, or functioning server-side validation code may prevent the submission from being processed.
• Temporary application configuration changes, database problems or application restarts may prevent the submission from being processed.

For all of these scenarios, it may still be possible, depending on the software on the web page or server, that the user may experience what seems to be a successful result, either by seeing an explicit success message, or by not seeing an explicit error message.