I was in a small barn on a heap of dung, I was standing in the corner right next to the walls. I took off my combat boots so I could repair them. However, I accidentally dropped them to the surrounding instead of taking them into my hands. This made the boots (including combat knife) disappear. I searched the whole barn and also checked outside of it (close to the walls) but could not find them.

This happened on the server DayZ EU - DE 7582 (Temporary).