Rescuing a possibly corrupt PDF in Acrobat [duplicate]

Did you ever use "Save as..." and choose a different filename after your page replacing operations?

With "Save as..." you'll notice that Acrobat indicates various steps of "consolidations" and "optimizations" while it saves the file.

Simple "Save" will not do that. For example, if you "Delete" a page, a "Save" will mark the page + its content just as "hidden", while all the 'deleted' page's bits+bytes are still part of the file. The "Save as..." would remove these bits+bytes.

If you did in fact always use "Save as...", you should try and re-distill the PDF:

If you have a full version of Acrobat (not just AcroReader), print the file to the printer called "Acrobat PDF" and choose a different filename.

If you only have Acrobat Reader, you could use Ghostscript with a commandline similar to:

 gswin32c.exe ^
    -sDEVICE=pdfwrite ^
    -dBATCH ^
    -dNOPAUSE ^
    -sOutputFile=my-redistilled-original.pdf ^
     c:/path/to/original.pdf`

I have resolved a similar problem in the past just by re-printing the the whole document as a PDF. Worked like a charm in that case.