Check to ensure that the water filter has been correctly installed and has been fully rotated, sitting snugly in its niche.
After continuous prolonged use of the filter, the water system may be subject to low pressure. Cease attempts to dispense water or ice for five minutes, then try again. If the dispenser still is not functioning properly, the water pressure may generally be too low. Have it checked by a qualified person.
The shut-off valve may not be completely open. Adjust the shut-off valve so that it is open completely.
The water connection line may have kinks in it. Shut off the water supply and then straighten out the kinks. Have any damaged water connection lines replaced with original manufacturer parts, which can be purchased from your dealer.
The water filter is old or clogged. A replacement water filter can be purchased from your dealer.