Certain threats out there are dangerous enough to cause major entities to warn against them. In particular, a recent malware by the name of VPNFilter has been deemed dangerous and prevalent enough that the FBI has addressed it. Since the malware targets routers (probably not your first guess in terms of possible vulnerabilities), it has considerable potential to become a nuisance for your organization.
QuestingHound Technology Partners Blog
One experience that almost everyone has been involved in is the clashing of personalities. This is only natural, as different people are born with different predispositions and are raised in differing environments. However, in the business world, one should do their best to keep personal differences from affecting the professional relationships they form.