Some users may encounter the situation that they can't preview the courseware when using the Chang Yan Teaching Link, and some users also have the problem of failure to upload and download resources. What should I do? Bian Xiao has brought a solution, I hope it will help you!

Solution:

1. This is caused by unstable network service. Before previewing and uploading, please check your network settings and ensure that the network connection is normal.

2. If the above methods fail, try to contact the official customer service.