If you've used this Adobe Acrobat quick-load tip, then you might run into the same problem I did: I recently went found a form online that I needed to update and print. But, when the form openned, I couldn't update it. I tried double clicking on a field, and it told me,
The 'Updater' plug-in has been removed. Please re-install Acrobat to continue viewing the current file.
I imagine that since the form is editable, and the updater plug-in isn't available to update Acrobat, this is probably the reason for the error. So, I started off looking for the updater plug-in, and found out that all I need are two files to enable form editing: AcroForm.api and EScript.api. If you need the updater capability, I believe you'll need the following (but don't quote me): Updater.api, EScript.api, Soap.api, and WebLink.api - you may need more, but I think these are needed at the minimum.
It's a pretty manual process to find what you need, but it only took me about 5 minutes. Hopefully, this might help others who've used this quick-load tip.