This time, paper was stuck between trays - all trays should be removed to get to torn paper. Small torn paper was stuck in the middle ie at the point where upper and lower tray meet.
Solid ink that was first to be taken inside of printer's catridge was deformed and thus printer reported that there is no ink present although it was filled up full. Once it was removed out of (with the help of office knife) and replaced with healthy chunks, it was ready again.