Multiple times the same question

In this thread I will post questions that exist several times and to which I could not find any info. You are welcome to do the same.

Such a thread was already once but this was locked because of abuse. I hope that is not the case here.

there are many questions because they seem unsolvable, however, these were years ago and there may be new information. It will be extremely hard to solve some but if someone does, that person has a jackpot