It is unclear exactly what, but something is happening to seemingly sometimes cause market stalls to but out and not be rentable, they seem stuck based upon who rented them last. Maybe it happens if someone rents a stall and is logged out when the timer would expire? But if that is the cause, I do not know. For example, right now every market stall is bugged, but people seemed to be using them earlier.
While I do not know for sure, this seems to happen when people log off before the timer finishes? Even if we can't fix this bug(it may be hard to fix) could we add a warning to the rent dialogue, prominently, in a special color and caps to NOT log off while the stall is rented, because it will bug it out until the next reset?
One stall was working a short time ago, while two others were bugged. Someone rented it and used it but logged before it finished and now it is bugged.