During the battle at the Goblin cave (passage on stairs leading to Caer Lem), one of the goblins desingaged from my created halfing rogue and hid behind a corner, thus breaking Line of Sight. On my turn, I chased it around the corner, but couldnt know for sure in what square it was on, so I tried to decide where to move based on the projected white lines on the movement preview. In one of the possible positions to move, the lines didnt show at all, so I believed that was a position where I would be in melee with it, so I clicked. It was actually the square the goblin was in, so we overlaped and I couldnt attack.
<a href="https://ibb.co/6vvSv51"><img src="https://i.ibb.co/z88g8w7/20210328231006-1.jpg" alt="20210328231006-1" border="0" /></a>