Scorm will not load because playbar images generate 503 errors

I recently started having this problem with Captivate 19.

After pressing "enter" on a SCORM module in moodle, it keeps showing the loading circle indefinitely.

When the page is refreshed, the module works as expected. Also, when I remove the playbar the SCORM loads as expected.

Errors in console:

First a bunch of 503's on playbar images eg:

/lms/pluginfile.php/98/mod_scorm/content/6/assets/playbar/PlaybarIcons/CC.png:1 GET  503

Then a drawimage error:

CPM.js:1645 Uncaught DOMException: Failed to execute 'drawImage' on 'CanvasRenderingContext2D': The HTMLImageElement provided is in the 'broken' state.

    at cp.PB.PlayBarButton.onMouseOut (https://mysite.com/lms/pluginfile.php/98/mod_scorm/content/6/assets/js/CPM.js:1645:311)

    at cp.PB.PlayBarButton.refresh (https://mysite.com/lms/pluginfile.php/98/mod_scorm/content/6/assets/js/CPM.js:1643:466)

    at cp.PB.PlayBarButton.setPosNWidth (https://mysite.com/lms/pluginfile.php/98/mod_scorm/content/6/assets/js/CPM.js:1641:55)

    at cp.PB.playBarConstruct.initComponents (https://mysite.com/lms/pluginfile.php/98/mod_scorm/content/6/assets/js/CPM.js:1669:144)

I have never had this problem in the past, just recently after making changes to old html5 captivate files in captivate 19 has this problem started. How do I fix this problem with the playbar in captivate 19?