Most of the following product manual is illegible when opened with SumatraPDF: Manual.
Be sure to download it first then open with SumatraPDF as the browser will probably render it correctly.
Note that only the first and last bookmarks are correctly rendered.
All other pages are not.
Other PDF viewers do not have the problem.
There seem to be errors in the file structure that cause problems for other pdf handlers e.g. sumatraPDF reports creation as september 2006 whils another app says december 1899 (i.e. before time began for computers) they all agree it was modified january 2007 and I suspect some of the faults may lie there, since it seems the first and last page have been manipulated around from an original 2 page “spread”
Trying to open the file with pdf meta editors in repair mode results in all the “blobs” being deleted as illegal characters and when opened in an editor the apparent ORC layout of accented characters is highly erratic.
It may be possible to restructure the file with Adobe products but if asked to repair by a client I’d advise to start again with new artwork
I can confirm, the file is definitely damaged. However it is clear that Firefox’s pdf.js, Microsoft Edge etc. can all handle the corrupted PDF stream far better than the muPDF version used by Sumatra 3.1.2 (I haven’t checked with the latest muPDF version to see whether it’s any better in this respect).