How to decipher the MS?

[Jorge_Stolfi]

Are you sure you believe that the manuscript can be decyphered? All attempts to do so have failed. By many professionals in the fields of cryptography and linguistics using deep computational algorithms. They were all unsuccessful. Almost every language has been put forward as a candidate for being the text in the invented manuscript alphabet.

There are many codes -- even simple ones that a nerd could have used in the 1400s -- that cannot be cracked by any "deep computational algorithms".  And no cryptographic code is as hard to crack as a language you don't know.

No, it is not true that "almost every language" has been seriously tried.  Not even every "European" language.  Énd iú mâst nót ónli gués d lánguaj bât ôuso d spélin sístem - uitx fór sâm lánguajis mêi bí véri dífren fróm d stândar uân.  Here is the same Mandarin sentence in four widely used romanizations:

Pinyin with diacritics:   Zhè shì yī běn shénmì de shū
Pinyin with numeric suffix tones: Zhe4 shi4 yi1 ben3 shen2 mi4 de shu1
Wade-Giles: Chih^4 shih^4 i^1 pen^3 shen^2-mi^4 te^5 shu^1
Gwoyeh Romatzyh: Jeyh shyr i been shenmih de shu

And then there are the changes that the candidate language must have undergone in the last 600 years.

And then you must account for errors - by the modern transcribers, by eventual Retouchers, by the Scribe, and by the Author himself.  If the error rate is 5%, it is already a problem for some startistical analyses and cracking methods. What if 30% of the words were inconsistently misspelled?

All the best, --jorge