Error: The configuration section 'system.webServer/rewrite/globalRules' cannot be read

Hi everyone, first time here.

so, i have a windows 2012 with a few sites published already.

one of my employers asked me to have suport of tomcat for java use, so i instaled ARR 3.0 beta, but when i tryed to click on "server proxy Settings", i received the error:

---------------------------
Application Request Routing
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There was an error while performing this operation.

Details:

Filename: \\?\C:\Windows\system32\inetsrv\config\applicationHost.config

Error: The configuration section 'system.webServer/rewrite/globalRules' cannot be read because it is missing a section declaration

i checked the file to see if the session reference globalrules exist there, but nothing... its missing.

anyone know how to fix it ?

thanks all, and sorry for the bad english, not main language.