We have a website that was working perfectly fine yesterday, but for some reason one of the pages are returning a "page not found" error today. The php page does exist and I've not made any coding changes. I've contacted the webhost and they contend that no changes were made to the linux server. So i'm stumped, what reasons could there be for a 404 error when nothing seemingly has changed?
As a bit of background, our site is used for collecting and reporting KPIs. On one page users enter comments that will later be included in a generated PDF document. This page's "Save" button calls a processing page ("save_individual_kpis_comments.php") to enter the comments into a database. It is at this point where the processing page is suddenly throwing a "page not found" error. As I've already said, nothing has changed on the coding side and I can see that this function was used yesterday to enter records into the relevant table. Funnily when I retry or type the URL into the browser it does seem to run the PHP code and attempts to close the page after processing, however nothing is actually entered into the database.
I'm not the programmer who setup this website and my php knowledge is limited so trouble shooting has been difficult. Could anyone point me in the right direction here?