There are several events or conditions that can prevent the performance of a contract by either or both of the parties. Some common examples include:
1.) The death or incapacity of one of the parties: If one of the parties dies or becomes incapacitated, they may no longer be able to fulfill their obligations under the contract.
2.) The destruction of the subject matter of the contract: If the subject matter of the contract is destroyed or rendered unusable, the contract may be impossible to perform.
3.) A change in law: If a change in the law makes it illegal or impossible to fulfill the contract, either party may be excused from performing.
4.) Impossibility or impracticality: If it becomes impossible or impractical to perform the contract, either party may be excused from performing.
5.) Breach of contract by the other party: If one party breaches the contract, the other party may be excused from performing.
In any of these cases, the parties may be able to terminate the contract or seek legal remedies such as damages. It is important for parties to carefully consider these potential obstacles when entering into a contract, and to include provisions in the contract that address these issues.