Apparently, China has "major issues" it wants Microsoft to explain…
In July of 2014, China raided Microsoft’s local offices and confiscated a lot of data as part of an antitrust investigation. On 2016-01-05, Chinese regulators demanded that Microsoft 
explain “major issues it discovered with that data”. This was the first time in over a year that China gave any indication that their antitrust investigation would be moving forward.
Microsoft has publicly stated that it is “serious” about complying with Chinese law and to addressing SAIC’s (China’s State Administration for Industry and Commerce) concerns.
At the beginning of the investigation, China said it was interested in information on how both Windows and Office were bundled, about compatibility between the two and other unnamed concerns.
China’s most recent demands haven’t been clarified or spelled out, but SAIC has asked Microsoft to submit their “defense in a timely manner.”
God knows what they need to defend, or what Microsoft needs to respond to.
Some are speculating that this is retaliation due to Microsoft retiring Windows XP and discontinuing support for it to any and all customers – including the Chinese government and its citizens. China had asked Microsoft to extend XP’s lifespan. Microsoft refused. China said, “pretty please;” and Microsoft STILL said no. China has banned the use of Windows 8 on any government computers.
