At the beginning I did not pay attention enough with numbers, now they are realistic according history, but now I am exhausted to check upper and lower case and see no more source of errors
Hello Flobert,
Maybe you didn't use the correct alphabet: It has a length of 62 characters and consists of the three partial alphabets upper-case letters, lower-case letters, and the 10 digits (0, …, 9). These three partial alphabets have to be arranged in the right order. Not to pay attention to this and only use a 26-character alphabet like done in history is a common mistake solvers initially make.
If this hint doesn't help, please send me an email with your solution and the alphabet used.
Best regards, Bernhard