The main reason may be that the SCORM package is not updated, meaning it lacks compatibility with the latest browsers when running in HTML5. In order to solve this issue Flash must be enabled on the browser, however, this is only a short term solution as Flash will be deprecated in 2020.
Our recommendation is to update SCORM so that it uses HTML5 instead of Flash and also to update your browser for you to achieve the best results.
*The required version for uploading SCORM to the portal is 1.2
For more info follow this link