1.  Non-stop gossiping:
Gossiping in the workplace is a general aspect. But very few are aware of the fact, how badly it can affect your professional life. Yes, as the gossiping has all the potential to harm your professional life, it is advised to be away from it, though you find it hard for a certain period of time till you get used to it. Gossiping about someone is not at all accidental at any point of time; it is a mistake that is done purposefully to harm someone’s reputation in the company. So, as this act can be considered as a form of bullying, those who gossip inside the company can be easily terminated, if this mistake is repeated continuously.   

2.  Not keeping the company’s secret as a secret:

As an employee, this can be considered as your biggest mistake you can ever commit in your professional life which has no chance of survival in the company without any pardons. Every company will be having few confidential matters that they don’t want to reveal publically. So, in such situations, normally, they will ask their employees to maintain that secrecy without revealing it anywhere outside. At this situation, if an employee is trying to or will reveal any confidential matters that can harm the company’s profit or its prestige, then no doubt that employee will be fired without pardoning or giving a second chance to them.