Gear box problem, stuck in first gear

[jbd40]

Hi all, new too site and seeking some advice / recommendations. Have an 08 d40 (Spanish built) and is stuck in first gear. never had any problems grinding or even noises out of gear box and had only been driving 20 mins prior to problem. Clutch working and gear stick feels like in natural but is stuck in gear still. Any help advice would be very much appreciated