Index.php is the only way?

Before you say anything, I DID search and couldn’t find anybody with the same problem. If you know of a topic that’s resolved with the same issue, feel free to point me in that direction. Thanks.

SO. I have this blog. I’ve been using WordPress for over a year, and I’m pretty good with it’s inner workings. To a certain extent.

I used to have everything set up simply. It was mywebsite.com/about/ would lead to the about page … that’s how I’ve always coded my designs for WordPress-run websites.

But now, all of a sudden, it’ll bring up an error. It won’t show me the about page unless I specify mywebsite.com/index.php/about/. Why does the index.php have to be there?

It was never there before. And I’ve told WordPress to use date-and-name based permalinks, like I always have. I just don’t like that index.php. I tried removing it through the custom permalink structure input, but it doesn’t do anything.

So what can I do to get rid of the index.php? Or does it absolutely have to be there?

Any help is appreciated. Thanks.