Artboards disappear and is replaced by guides for artboard when reopening an existing document
Using Illustrator Version 22.0.1 on PC. Also happens on my Imac at work as well.
This happens from time to time but does get somewhat annoying when it does.
When I open an existing document, the artboards are all gone except for one artboard and what is left instead are guides for where those artboards are meant to be, and a new layer has been created in the layers panel with the name 'Guide For Artboards'.
There isn't anything out of the ordinary I do when saving a file so I have no idea why it likes to do this from time to time.
You need save files in Illustrator CS4 or higher version to preserve the artboards. If any file file is saved below that version all the artboards are converted into guides.
ah, great that makes sense. I save legacy generally because some clients don't use CC.
Egor Chistyakov commented
Make sure you save in version CS4 or higher, because multiple artboards feature exists only in this and newer versions.