Unable to save the Tour Story Map template when an audio or a video HTML tag is included in the caption.
Last Published: August 18, 2017ArcGIS Online
Bug ID Number
September 28, 2015
June 2, 2021
After review by the development team, it has been determined that this issue is related to a known limitation with the software that lies outside of Esri's control. The issue's Additional Information section may contain further explanation.
Closing this out as known limit of feature services and how it filters web content:
Workaround is to use different method to add images with these captions.
If the images for the Map Tour or the thumbnail are hosted in ArcGIS Online, the tour is possible to be saved.