Do you let me know what kind of content I should put in the error-page like "404 page not found"?
"Unfortunately an error has occurred during the processing of your page request."
"Page Not Found! Check the URL"
"Sorry an error has occurred! Please Try again."
"We're sorry, we couldn't find the page you requested."
The content should be target user perspective. Means that target user should easily understand what's happening and what he should do?