the only reason why you can see letters outside of Base58 character set such as "o" or letters outside of hexadecimal characters is when you encrypt your wallet file. in which case you should also see characters such as "+" and "=" since it is going to be in base64 format. in this case you will need the password for it.
Hello, yes there are some "+" and yes i have the password for it. But how can i do to convert it? reinstal multibit and import this file and encript with passord... it work?
thank you
if the file was encrypted with Multibit then the easiest way to decrypt it properly is to use the same wallet software (the same Multibit version) that you used in first place.
there is a link for each version here:
https://multibit.org/help/hd0.3/change-password.htmlit is worth reading this blog post also:
https://multibit.org/blog/2017/07/26/multibit-shutdown.htmlit has a video at the bottom and also it introduces this tool:
https://github.com/Multibit-Legacy/read-multibit-wallet-file so that you can extract the keys from your Multibit wallet file.