If you already tried the previous suggestion (grind at the most coarse setting) and you still get no water, it may be the SBS brew valve.
As a test, run a blank shot by telling the machine you are going to add preground coffee but don't add any coffee. When you start your shot you should get plain water (probably tea colored as it flushes out some old coffee left behind from previous brews).
If you still get no water, then it is either your brew filter screen is plugged or the SBS brew valve is plugged.
Remove the filter screen and hold it to the light, can you see through all or most of the tiny holes? If not, soak it in a good coffee detergent and scrub it with a toothbrush until the holes are clean (DO NOT USE A NEEDLE TO CLEAN THE HOLES).
If it is the SBS brew valve, you can open it fairly easily to clean it but there are a couple of tiny parts and a spring so be careful.
And final thoughts - the SBS brew valve can be defective - I've had some that were too tight and simply wouldn't allow any water to flow at all. But since yours was working before, it probably just needs cleaning.
Answers & Comments
If you already tried the previous suggestion (grind at the most coarse setting) and you still get no water, it may be the SBS brew valve.
As a test, run a blank shot by telling the machine you are going to add preground coffee but don't add any coffee. When you start your shot you should get plain water (probably tea colored as it flushes out some old coffee left behind from previous brews).
If you still get no water, then it is either your brew filter screen is plugged or the SBS brew valve is plugged.
Remove the filter screen and hold it to the light, can you see through all or most of the tiny holes? If not, soak it in a good coffee detergent and scrub it with a toothbrush until the holes are clean (DO NOT USE A NEEDLE TO CLEAN THE HOLES).
If it is the SBS brew valve, you can open it fairly easily to clean it but there are a couple of tiny parts and a spring so be careful.
And final thoughts - the SBS brew valve can be defective - I've had some that were too tight and simply wouldn't allow any water to flow at all. But since yours was working before, it probably just needs cleaning.