Hi Nigel
This is likely to affect some SCORM packages that save user progress -.Totara has produced a fix for this TL-22621 in the October 2019 release.
More information on how this was fixed is in the release notes
SCORM no longer uses synchronous XHR requests for interaction
Chrome, in an upcoming release, will be removing the ability to make
synchronous XHR requests during page unload events, including beforeunload,
unload, pagehide and visibilitychanged.
If JavaScript code attempts to make such a request, the request will fail.
This functionality is often used by SCORM to perform a last-second save of
the user's progress at the time the user leaves the page. Totara sends this
request to the server using XHR. As a consequence of the change Chrome is
making, the user's progress would not be saved.
The fix introduced with this patch detects page unload events, and if the
SCORM package attempts to save state or communicate with the server during
unload, the navigation.sendBeacon API will be used (if available) instead
of a synchronous XHR request. The purpose of the navigation.sendBeacon API
is in line with this use, and it is one of two approaches recommended by
Chrome.
The original timeframe for this change in Chrome was with Chrome 78 due out
this month. However Chrome has pushed this back now to Chrome 80. More
information on this change in Chrome can be found at
https://www.chromestatus.com/feature/4664843055398912
We recommend all sites that make use of SCORM and who have users running
Chrome to update their Totara installations in advance of the Chrome 80
release.
regards