xdmcp connection failed: cannot open display [2]

I was working comfortably with xbrowser.

But once i logged out and when i tried to access a host from xbrowser, just a grey screen appears. No login screen appears. the log file shows :
Xdmcp Request Address: 172.17.0.26
Xdmcp Connection Address 0: 172.17.0.141
Xdmcp: sent a REQUEST message
Xdmcp: received an ACCEPT message
Xdmcp: sent a MANAGE message.
Xdmcp: Timed out, state 8. Retransmissions: 0
Xdmcp: sent a MANAGE message.
Xdmcp: Timed out, state 8. Retransmissions: 1
Xdmcp: sent a MANAGE message.
Xdmcp: Timed out, state 8. Retransmissions: 2
Xdmcp: sent a MANAGE message.
Xdmcp: received a FAILED message.
Xdmcp fatal error: Session failed Session 86 failed for display acer-ce0ab306db:0: Cannot open display

I am also attaching the log file.

This problem is usually caused by 1) firewall on your PC, 2) incorrect entry in the DNS, or 3) improper operation of xdm.

In each case, try the followings:

1) Follow the instruction on Xmanager FAQ # 12 and configure your firewall.

/products/xmg_faq.html#p12

2) Add your IP address in /etc/hosts like this:

172.16.2.120 PC_NAME

3) Restart the xdm process.

If your problem persists, please send us the following information:

1. Name/version of the remote host.
2. See if other users can log in to that machine.
3. From your computer, try logging in to a different account.

Hope this helps.

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Technical Support

I was facing same problem.

It got resolved after closing local firwall.

Thanks

Gurvinder