I have some Manipulate/Animate plots (mostly relating to geometry and geography) which look good after evaluation. But when I saved and reopen the notebook again, many of them will turn into error images in red color. Sometimes, I can see that the geometry/geography plots turn into some matrixes with some numerical entries being changed, while the slider of the animation is still running.
Normally, I need to evaluate the entire notebook again to turn them back into normal images again. Why would that happen and how to fix?
The problems become even worse when the notebook is uploaded to the cloud. Many of them can't even be shown no matter how many times I have refreshed the web page.
Many thanks!
