It is not possible to tag a build any more. In the past (issue JENKINS-4374) it was not possible to "Tag all upstream builds at once", but it was possible to tag one build per time.

Whenever we try to tag a build it shows us a message saying "Marcação está em progresso:" (meaning Tagging is in progress) and a button saying "Limpar erro para tentar novamente" (meaning Clear errors and retry). Moreover we get no log errors neither tag in the source code.

According to mindless, he is also having a similar issue in SVN. Mindless also said the following in an issue comment (JENKINS-4374).
"From what I can tell in the src, the screen with "Tagging is in progress" should show output from the cvs tag command and several other status messages about what it's doing.. the "Clear error to retry" button is only there when the operation is done.. so the fact you see this right away and with no log output is quite odd."

I set the log level to ALL to try to understand the problem. The log is attached.
What is important to say is that hudson is trying to use the user 'anonymous' (and 'SYSTEM' in some cases), but I'm logged in with the 'admin' user.

If it is not possible to provide a fix in a mean time, please, provide a work around. Since, right now, it is not possible to tag a build at all.