After uploading a PDF file with annotations in the homework activity, there is an exception on the page when opening the annotated file.
Question:
1. Can only view the first page content, unable to view the next page content, clicking on the next page has no response
2. The full screen button has no effect.
Page flipping method:
At present, only the previous page and dropdown page selection are useful, and there is a bug on the next page, which has a poor user experience.