Irregular production. Causes damaging mistakes to the company.
Makes simple things get complicated.
The second most troublesome situation is one where you are working with people who are emotionally unstable and their mood fluctuates constantly. Their ups and downs tend to lead to costly mistakes and create unnecessary problems. Their production is not regular and they are often sick or injured or have some issue that requires regular attention.
Reliability and reproducibility are crucial elements in running a business smoothly. A business owner needs to count on the people they are working with. Having unstable people on their team undermines that and puts the owner in firefighting mode through the day. Such people absorb the attention of the business owner and wear them out.
The solution to this situation is to detect these people and stabilize them rapidly. If this is not possible, the entrepreneur would be better off letting the person go. It takes some efforts and know-how to stabilize an unstable coworker. If their work is very valuable, the effort is worth it.