I constantly get the same error during svn update or compare operations in IntelliJ Idea Community edition:
svn: E175002: Received fatal alert: unexpected_messag
Adding -Dsvnkit.http.sslProtocols=SSLv3 option in IDEA_HOME\bin\idea.exe.vmoptions file resolved issue for me.
-Dsvnkit.http.sslProtocols=SSLv3
IDEA_HOME\bin\idea.exe.vmoptions
See http://youtrack.jetbrains.com/issue/IDEA-90335