OSCAR requires pop-ups to be allowed for changing the schedule and assigning lab results.

Firefox has blocked a pop-up - 

If you see a bar along the top of Firefox -

Select Options on the right side -

In the menu that drops down, select Allow pop-ups for your specific URL.

Repeat any time in your OSCAR that you see the bar along the top blocking a popup! Once done the browser retains the settings, this will not need to be done every time you are in your OSCAR.

To check the pop-up setting without having the bar come up at the top of Firefox First – 

Select the menu button in the upper right;

In the menu that comes down, select Options;

In the Options menu screen, select Content from the left pane;

In the Content options, select Exceptions on the right side;

This will open an Allowed Sites – Pop-ups window, here you can enter your OSCAR secure URL to tell Firefox to allow pop-ups from it. Once it is in the list under Site, select Save Changes.