Iveco 50-C-13 Non Start?

The engine in this minibus usually starts after 3 or 4 turns of the starter. I started it no problem this morning and left it running about 5 mins. I then turned off, but when I tried to restart 30 mins later the starter turns the engine over but will not run or even attempt to start. I checked the fuses , all ok. There is no code light on. All light on dash ok. When turning over the red injector warning lamp is flashing on the dash, but I am not sure if it does this anyway.
Has anyone got any ideas?