SCORM-Module does not open twice in Firefox?

Hi all,

I'm afraid this is tricky and I really hope one of you out there can help me out:

• I've created an eTraining with Rise and exported it as a SCORM-Module - see attached Screenshot for settings in Rise.
• I then implemented the SCORM Module in our LMS - see attached Screenshot for LMS-Settings.
• Everything seems to work fine: When I click on the eTraining in the LMS the eTraining opens and can be worked with. After finishing the eTraining the LMS tracks learners status correctly as "completed".

The problem:

• The problem is this: When I try to reopen the eTraining it is not displayed any more once I have finished it. For a very short moment the loading page is displayed, but then the browser page goes blank - and stays that way. 
  This only happens when using the Firefox-Browser, though.

This is what I have tried so far:

• using a private browser window
• deactivating all browser extensions
• clicking on the "leave course" link after finishing the eTraining 

none of this had any effect.

The Firefox web developer toolbar shows some errors - see attached screenshot - but I'm not tech-savvy enough to make sense of it or to know what I have to do to stop this from happening.

I would really like to avoid telling everyone they have to use a different browser so help is really appreciated.

Kind regards,

Frank