Another challenge that managers today face is globalization, no matter how large or small a company they manage. Companies are competing around the world, and the playing field is by no means level. Each country has its own laws and regulations that add to the cost of doing business to very different extents. In a country that does not provide regulation for the safety of its workers, does not have child labor laws, or does not regulate the safety of products, a company has considerably less overhead and can charge competitive prices, winning out over a company that operates with such constraints. With the nearly universal availability of the internet, people can search for products all over the world and can now compare prices of products as never before.
One of the problems with this question is that it is very vague. A manager at a local restaurant franchise in a small town in Canada faces very different challenges than a manager at a global oil company in the Middle East or the manager of a technology company in China. Also, a low-level project manager faces far different issues than the manager of a large division.
One challenge managers now face is increasing regulatory complexity. Within much of the developed world, this includes equal opportunity laws and required accommodations. Another regulatory issue in global corporations is the tension between anti-corruption regulations and many local cultures in which corruption is endemic. A manager in many areas in sub-Saharan Africa has the choice between paying bribes or being unable to get the permits necessary for normal business activities.
Technology is also an area that can be challenging for managers. Employees need access to technology to function, but technology can also lead to security leaks. Also, there is the question of whether employees should be allowed to use personal technology for business (a security and standardization issue) or allowed to do personal tasks using company technology.