Problems with creating XNB - Windows 7

Hello, this is my first post, and I have 2 questions.

I have installed today the MonoGame for Visual Studio version in downloads page, under Development Builds I believe it to be the same as:<default>&guest=1#!ossgocr .

Everytime when I try to create a XNB file with XNB Builder or XNA Content Compiler, I receive the following message:

There was an error while deserializing intermediate XML. //The character chain must be one character long//. The part between // it’s my translation, it comes originally in portuguese as: //A cadeia de caracteres deve ter o comprimento de exatamente um caractere//

When I try to create it with MonoGame Pipeline, it runs, says MGCB stopped working, but when I go check it the xnb file is there, created. And this is after a long afternoon with the problem, during which I:
- installed Monogame 3.2 stable release
- installed OpenAl from MonoGame folder
- installed the version I say above over it
- installed XNA framework
- uninstalled MonoGame
- reset the computer
- reinstalled MonoGame
It simply didn’t work before, It sent an error that I can’t reproduce now so I can’t show it here, and I honestly can’t say how it started working, it just did. And it’s not the prettiest thing ever, but I’ll take it.

But XNB Builder and XNA Content Compiler both still don’t and I’d like help with that if possible.

Second, while looking at the files in both MonoGame and MSBuilds/MonoGame, I noticed there was no protobuild.exe file to be found. I found about it while trying to solve the first problem.

It’s normal for it not to be there? Should I worry about it?

Thanks for your time, everyone.