Haven't seen that error message, but I have tried to use Mimic's on-screen video recording. My suggestion is, don't. I've never been happy with the results.
It's a lot more work on your part, but you can use keyframes to build your own animation. Start with an image of the background and an image of the bit of the slider that moves. Set keyframes for the start and end position of the slider and there you go.
And send lots of suggestions to Madcap for ways that this can be improved. https://www.madcapsoftware.com/feedback/featurerequest.aspx