Tencent's explanation is:
In order to provide better product experience and service for QQ space enthusiasts, QQ space has recently upgraded and maintained some modules. In the process of maintenance, it may affect the normal use of some functions of the space. For example, the video and flash in the space can't be displayed, some pictures in the album can't be browsed temporarily, and the signature file can't be displayed temporarily. Please forgive the inconvenience caused to everyone. Meanwhile, the staff are working hard. After upgrading and maintenance, you will get a better space experience! thank you