When commercial loans are renewed (and they are because commercial loans are usually rolled over and not paid off, ie interest only) things like the occupancy rate, rent cost, creditworthiness of lessees and other things are factored into the new loan terms. So if the rental rate is lower then interest will be higher on the loan. Or the loan provider will okay a smaller portion of the loan requiring you to cough up the difference.

Example a $10m building, you put $1m down on. You go to refinance the loan and they are only willing to float you $7m now because you arent able to charge as much rent to tenants. Thus requiring you to come up with $2m or lose your $1m investment and the building.