Captivate 9 and Totara SCORM http

Am I correct in assuming you are publishing to SWF?

If so, the link that the LMS is tripping over is likely to be found in the HTM file published with the SWF file.  It is the HTM file that actually launches the SWF.  However, in the HTML code of this HTM file there is a link to the Adobe web page where you can download and install the Flash Player plugin.  This link is HTTP and is put there in case the end user tries to play the course module without a Flash Player installed in their web browser.

Your LMS will be secured, so it wants everything in the course to be also secured (hence the HTTPS) but this particular link is by default only HTTP.

You can manually find and change the link in each and every finally published HTM file you need to upload to your LMS.  Or alternatively you can locate the HTM template file used by Captivate to publish these HTM files and change the link there.  This will then mean that all HTM files published for that type of output (e.g. SCORM 1.2) will always be formatted the way you want.

The HTM template files are found in the Captivate install directory inside a Templates folder buried down a few folder levels and must be the specific HTM used for your particular LMS output. (SCORM 1.2 or 2004.)