It is not uncommon for users to want to upload their own content into our Lesson Library.
For Microsoft formats such as Powerpoint, Word, etc, LearnCube will automatically convert these to a PDF format in order to make it more user-friendly in the whiteboard.
We do this because PDF is a more universally reliable format (able to display on any device) and all users can annotate on a PDF embedded in the LearnCube whiteboard (users cannot annotate on a Powerpoint in the same way).
Also, we've found PowerPoints often become very large files when they include imagery and multi-media, video, etc.
What we recommend is to convert PowerPoints to PDF
Convert your PowerPoints to PDF for free using ilovepdf.com before if you wish
For large files of over 10MB, we recommend you also compress large files so they load faster even if your students have low bandwidth.