When searching by Post, I get the following error: The website cannot display the page HTTP 500 Most likely causes: The website is under maintenance. The website has a programming error. What you can try: Refresh the page. Go back to the previous page. More information This error (HTTP 500 Internal Server Error) means that the website you are visiting had a server problem which prevented the webpage from displaying. For more information about HTTP errors, see Help
When you say searching by post, what exactly do you mean as there's lots of options on the search page. Do you mean searching for posts by a specific user?
I'm clicking the Search option on the top tool bar, then in the box I'm putting my search term and checking the "Show Posts" option.