If it is like the CD/DVD FSM programs I have (w115, w124, w140, r129, w211), the actual documents are just pdf files. What you need is the table of contents and listings to know which pdf file to look at. Another alternative is to install an older version of an alternate browser (e.g. waterfox, opera) from before 2020 and find a copy of flash from back then for the browser to use. Works for me when I still need to run some local flash files.

w124-zone.com used to provide an html version of the w124 pages, before it went away (it was a downloadable zip file of html pages, at least).

__________________
1976 240D [W115.117/616.916] (acq 11Jun76)
1990 MB 300D 2.5 Turbo [W124.128/602.962] (acq 4Sep15)
1991 SL250D (ex-300SL-24) [R129.061/OM602.962/722.618, was M104.981] (acq 25May12, converted to diesel)
1993 Jeep Cherokee [XJ] (acq 12Apr14)
2013 GLK250 BlueTec 4MATIC [X204.904/651.912] (acq 24Jan26)