What is the ruling of Islamic law regarding tenants remaining in an apartment, and does the landlords' failure to conclude new written contracts permit them to pay the rent to the court, and what is now obligatory upon them?

The Maliki school of thought permits the annual rental contract with the old owner and considers it non-binding. Therefore, the contracting parties have the right to annul it whenever they wish, and the tenant is only obligated to pay the rent for the period he occupied the property. According to the Hanafis, the contract is valid for the first year, and then it becomes binding for subsequent years if neither party annuls it at the beginning of each year. As for the Shafi'is, this contract is invalid and must be annulled, and the two parties (landlord and tenant) must revert to paying the fair market rent (ajrat al-mithl). Consequently, the tenant does not have the right to refuse to vacate the apartment, and he is not entitled to compensation unless he carried out beneficial repairs to the apartment with the owner's permission.