This could happen due to one of the following reasons:
- The file to be uploaded is password protected. Remove the password before uploading the file.
- The file to be uploaded contains macros. Disable any macros before uploading the file.
- The number of slides in a presentation exceeds the maximum allowed limit, which is 200 slides. The presentation fails to upload with a message "Maximum number of slides limit reached".
Workaround Split your presentation into two presentations and then upload it.