I have many MikroE development boards, and have NEVER had a single LED fail on any board.
Run the "LED curtain" example program with the supplied PIC18F87K22 PIM. All but 3 LEDs will flash (and 3 more LEDs that are not fitted)
LEDs for RG6, RG7, RF0 will not light - this is normal.
I have had buttons that are intermittent on older v6 boards, but not EasyPIC pro v7, which I have owned for many years and still works perfectly.
Test switches (and the 3 remaining LEDs) by setting all button press levels to Vcc, turning on all LEDs, hold down reset with one finger, press each button in turn with finger from other hand.
Should you find an intermittent button, press it hard many times and it may come back to life.
.... Unless you are talking about button bounce, which is normal and requires software debounce techniques.