First thought is page vs. window size. Some pages are designed for a fixed window size, particularly "dialog" windows that pop up in a plain frame (no menu, no toolbar, etc.).

Is it possible that you have zoomed the site, so the control panel is larger than will fit in the fixed window?

To reset the zoom level, you can use Ctrl+0 (that's a zero) or, if the menu is visible,

View menu > Zoom > Reset

When you are using the orange Firefox button (short menus), you can tap the Alt key or press F10 to display the classic menu bar to use the old View menu, but this might not work in a dialog pop-up.

Does that help?

If not, is it a site you can post a link to so people can see the problem?

Well its in a control panel so my login info would be needed. Its just this particular page... I have no idea what the issue is. Honestly I didn't do anything to zoom the site. what else could it be???

It's easy to zoom accidentally using the Ctrl key and the mouse wheel. But if you reset the zoom level and the page is still too large...

Let's try this test: we're going to open the control panel page in a new window.

If you right-click the page, is there a "This Frame" item on the menu?

If yes, expand that and choose Open Frame in a New Window.

If no, choose View Page Info and copy the URL. Then open a new window (Ctrl+N), paste the URL, and press Enter to open it.

Do you get normal scrollbars in the new window?

THANK YOU very much, I just zoomed out a bit!!! Thank you