"What's going on here?" error message and problems using Vimeo in Web Object widget
Using latest Captivate 8 on Windows 10. I have five 5-minute HD mp4 videos uploaded to Vimeo Plus account. I've used the Web Object learning interaction widget with the embed code from Vimeo on 5 blank slides in my Captivate project. I've extended both the widget and slide time on the Timeline to a few seconds past the actual length of the Vimeo video. In between each video slide I've place one or two quiz slides. After publishing and uploading to a live website everything seems to work very well except that occasionally a video will stop part way through and the Captivate project will immediately advance to the next quiz slide. This is erratic. In testing with multiple users one person may get through all videos O.K. but the next may have 1 to 4 interruptions. When I've tested it online I find the same erratic behavior.
I've tried putting a "Continue..." button after the video on the timeline. Video may still stop playing after a couple minutes but the slide now continues until the button is reached on the timeline. So that didn't solve the problem.
In the Widget Properties of the Web Object there is a preview button:

When I preview any of the 5 embedded videos I get this "What's going on?" message, however I can see the first frame of each video in the background and nevertheless it still seems to start o.k.

What does Adobe mean by "Please install Flash or upgrade your browser." I have Windows 10 which says I have the latest version of Flash Player. I also have Adobe Edge Animate installed.
Any help with correcting this problem would be greatly appreciated. I know I can simply insert the 5 videos into the project timeline and it will work, however these are large HD videos and with 2 or more users accessing at the same time we get some bandwidth problems. I thought that using Vimeo to stream the video contents would solve the bandwidth problem but having the videos cut-out midway is not acceptable. Has anyone else had good luck with using Vimeo in this manner? Are there some other methods I can try?
Thank you,
Tom
