My pdf has gone bad while editing, how do I go back to the version from last night?

On Windows you can try the Restore Previous Version command; On a Mac, use the Time Machine app. In the future, make sure to keep backup copies when working on a file, especially when doing something as unpredictable as editing a PDF's static contents.

in the future, to find the best place to post your message, use the list here, https://community.adobe.com/

p.s. i don't think the adobe website, and forums in particular, are easy to navigate, so don't spend a lot of time searching that forum list. do your best and we'll move the post (like this one has already been moved) if it helps you get responses.

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