Failed to initialize monitor Thread: Unable to establish loopback connection

Question

Since yesterday suddenly my Eclipse does not work anymore. The error is "Failed to initialize monitor Thread: Unable to establishe loopback connection". I googled and tried the following:

• IPv6 completely off, if I ping localhost I get back 127.0.0.1
• Firewall exceptions added for eclipse.exe and adb.exe
• Adb killed and re-started
• Reset Adb from eclipse
• Virus scanners off (temporarily)

Nothing seems to help, I'm lost. Besides, if I try to update I get the error message also:

Some sites could not be found. See the error log for more detail. Unable to read repository at http://dl-ssl.google.com/android/eclipse/content.xml. Permission denied: connect

.. I can browse from Eclipse (with the Internal Web Browser perspective), so there is an internet connection. Furthermore, no proxies, just a direct connection.

Answer 1

My solution was: Terminate my proxifier.exe

I guess eclipse doesn't like proxies

Answer 2

Solution : turn off Teredo Tunneling Pseudo-Interface.

This probably converts IP4 to IPv6 addresses or something, resulting in an IPv6 address for your localhost (strange though, that a PING still results in IP4). Anyway, turning it off (Device manager > View > Show hidden devices > right click on Teredo > disable) solves the problem!

I found out by doing a ipconfig /all in the NON working situation. It showed :

Tunnel adapter Teredo Tunneling Pseudo-Interface:

Connection-specific DNS Suffix . :

Description . . . . . . . . . . . : Teredo Tunneling Pseudo-Interface

Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0

DHCP Enabled. . . . . . . . . . . : No

Autoconfiguration Enabled . . . . : Yes

IPv6 Address. . . . . . . . . . . : 2001:0:5ef5:79fb:####:###:####:####(Preferred)

Link-local IPv6 Address . . . . . : fe80::3c47:###:####:#### (Preferred)

//edit : I guess it's a workaround untill Eclipse supports IPv6