Hi Marybeth,
What are you trying to share . Is it the published output or the presentation (pptx) itself ?
In case you are sharing the pptx, please use the package option under Presenter ribbon
If you want to share the published output, please zip the published output folder. It should play fine on all browsers.
If you are still facing problem, could you please share the zip/package with me at alpagarw@adobe.com ?
Thanks
Alpi Agarwal
Adobe Presenter Engineering Team