dlittell

Correct, it is working for us now.

I agree that it sounds like a conflict with another plugin. Considering that both of the other plugins are related to media, I suspect one or both may have a dependency on SaveSVG. Simple Image Sizes was also throwing an error about classes that weren’t found.

When the errors occurred, we had updated plugins in this order:
SafeSVG
Simple Image Sizes
Theme My Login

After reverting Safe SVG to 1.9.9 we found that the update worked fine if we updated plugins in the following order:

Theme My Login
Simple Image Sizes
Safe SVG

I am experiencing exactly the same issue exporting one of the forms on our site, but not with any other forms.

If I revert my site to a backup where there only a few entries, I can export the list just fine. I suspect the issue is some unexpected character or control code the users of my site are typing in a textbox, but I can’t be sure because there are too many entries to go through them all looking for strange characters in the data.