Okay, so I have about 25 layouts on this particular drawing that already have a default page setup assigned to them. I just created a new page setup and want to apply it to these layouts...but I cannot. I can select the right setup in the publish window but it does not stay current after publishing.
The problem also comes up if I do a "-purge" or wblock the entire drawing as to remove weird elements. The pagesetups then show as missing.
If I create a new drawing and setup the pagesetup for the first time AutoCAD will ask if I would like to apply to all layouts. Where is this option for existing drawings?
PUBLISH does not overwrite individual pagesetups: if you want to continue to use PUBLISH, you need to save the sheetsset in PUBLISH. Explore getting into SheetSet Manager for management of large collections of project files as you have.
To apply an imported pagesetup to a layout while in PLOT command, select/double-click it from the pulldown, then APPLY TO LAYOUT button to make it stick.
If you need to do multiple at once, you need to automate: since I missed if you noted whether the 25 are one file, or 25 files, you can try a search around these Autodesk forums for Lisp routines to do it such as:
All 25 layouts are part of one file. It just amazes me that AutoCAD would allow you to assign to all layouts in a new drawing but this cannot be invoked for existing layouts... It's even more strange that the only way to do it is by lisp or similar for existing layouts.
This should be an option for the "Check standards" feature as well.