If the course is not working in SCORM Cloud, something i definitely wrong.
Since you tell that the issues now also happen with older courses working before, you have first of all to look at what has changed outside of Captivate. Which browsers are used? Did you publish to SWF or to HTML? If it was to SWF, most browsers do not install the Flash Player plugin anymore by default, it has to be manually enabled. If you publish to HTML that cannot be the problem.
Second change which happened in a Chrome version: Autoplay disabled. Could that be the case?
How did you set up SCORM in CP2017?
Anyway, please tell which version you are using (full number as displayed under Help, About Captivate) and which OS? Do you create responsive or non-responsie projects? If the projects are non-responsive do you publish to HTML? If they are responsive and you use CP2017 which workflow: Fluid Boxes or Breakpoint views?
Has your LMS just implemented an update? Have changes been made to the network setup? It sounds like the problem is not in your courses since your old ones that used to work now have problems, but in either the LMS or the corporate network changing something that causes a communications failure.
We use Internet Explorer 11. I published to SWF here is my publish screen:
The Captivate version I am using is 10.0.1.285. The operating system is Windows 7 professional 64 bit.
The programs we create are always non-responsive published with SWF. The SCORM settings are:
SCORM 2004 4th edition
Completion Criteria: Quiz is passed or attempt limit reached
Success: Quiz is passed
Settings: required to take the quiz to continue
80% passing grade
if passing - continue
if failing - continue
As far as I know no they haven't. They have tried to recreate the error but are unable to. The company hasn't made any major changes just updates here and there to the versions we are using.
Publishing to SWF means you need to have Flash Player enabled in any browser. I see you publish to the desktop, is it included in Flash trusted locations?
How do I check to see if it's a flash trusted location?
I believe that spending time getting Flash to work is a futile effort. You might want to consider transitioning over from Flash to HTML5. Flash will only be supported by Adobe until the year-end of 2019, however, most browsers are being updated to disable Flash even earlier than that date. It's going to become increasingly more and more difficult to get Flash to work. You may want to test one of your courses with the HTML5 publishing workflow and see if your LMS and the various browsers your organization uses will work fine with it. Keep in mind that there are some features that were previously supported for Flash that are not supported in HTML5. Use the HTML5 Tracker (Found in the Project Menu) in Captivate to see if your project has anything incompatible with HTML5. Replace those items with something HTML5 compatible.