What browser are you using?
Have you tried to use another browser?
I've tried IE 9, Chrome 36 and Firefox 31. All give the same result.
I would recommand you to go in the extension menu and delete VSE extensions.
And after install the VSE extension again.
I think it will resolve you problem.
Removed both VSE extensions, and re-added, but no joy.
It's really strange, I get no error messages at all, and all of the other Policies display correctly.
Try to make as duplicate than edit that policy and see if you are able to save the changes or not.
The duplicate copy still has the same issue.
Is ePO installed in non-root drive (in different drive than C drive)? Do you see the issue if you install in C drive?
I have currently installed to the D: drive, so I will reinstall, and let you know the outcome.
Just do one thing, restart all ePO services and recheck in VSE 8.8 Patch 4 extension to see if it will help you or not.