Tuesday 10 January 2012

Problem with Google Chrome and Twitter

Google Chrome 16.0 and Twitter Direct Message Problem

First, I can't believe my version of Chrome is now on 16.0.912.75. It seems like only yesterday I had Chrome version 1 and it didn't change for a good while.

Unlike Internet Explorer which refuses to force automatic updates on their browser users which mean developers still have to cater for IE 6 and non standard compliant code due to IE 9 not being available on Win Vista or XP. I do appreciate that they automatically upgrade the browser when required.

However it does seem like FireFox (version 9.0.1 I am currently on now) and Chrome are in some kind of race to see who can get to version 100 first. I haven't exactly noticed many differences between all these nightly version changes so it must be bug fixing as if it isn't I have no idea what it is apart from security hole patches.

Anyway, I recently got a new laptop for work (a DELL, 64bit, quad core i5 Win7) which is good APART from the horrible, horrible flat mouse pad which seems to go into sticky scroll mode a lot. You know when suddenly the mouse cursor turns from a pointer into cross-hairs and as you move the cursor the whole page scrolls with it.

Tonight I noticed an issue with this and Twitter's new format for Direct Messages which open in a draggable DIV popup.

I went to write a Direct Message and the cursor went into sticky mode. I couldn't remove the mouse cursor from the pop div as wherever it went so did the popup box. Very annoying.

What was interesting was that as soon as this issue occurred my CPU and Memory for the Google Chrome.exe *32 process went shooting through the roof and my laptop turned into a helicopter. I honestly thought the machine was going to take off it was that loud from the hard-drive spinning away.

The only solution was to move the cursor off the webpage to the toolbar and kill the page totally and as I did the CPU and Memory dropped like a stone from a cliff.

This is obviously an issue with DELL's mousepad but it reminded me of an issue I had with my own HTML WYSIWYG editor which was a pop DIV you could drag about the screen.

The editor had a couple of listboxes on it for selecting fonts and sizes etc but because I had a a drag event attached to a mousedown and mousemove event it meant that you could never actually open the list and scroll it down to the bottom as if you did all that happened was the Editor moved around the screen.

It was a simple drag n drop solution which was fired by a mouse down event setting a flag so that when set any mouse move event moved the referenced DIV until a mouse up event set the flag off.

I got round the problem at first by just making the top and bottom sections of the DIV container for the editor draggable which did fix the issue but in the end I settled for what is getting more common as a solution for the old pop up window, the lightbox.

I don't know why Twitter need to make their new message pop div's draggable as they change the backgrounds opactity like a lightbox anyway so I don't see the point in the draggable effect at all.

I know it would certainly help with my DELL's sticky mousepad problem!

Wednesday 4 January 2012

Remote Desktop Access Denied Error

Troubleshooting Issues with Remote Desktop / Terminal Services


This morning I tried remotely accessing my work PC which is always left on from my home laptop.
However after my first attempt I was met with the following error which appears om the login screen on the remote PC.

"the refereced account is currently locked out and cannot be logged on to"


Locked out of PC


I tried pinging the PC and could get a response fine but running the reboot command:


shutdown -m \\mypcname-r -f

I just got an "Access Denied" error.

I could login fine the night before and I hadn't installed anything new. I ran a virus scan which didn't pick anything up.

After connecting to the Virtual Private Network (VPN) I tried running the following command from the RUN prompt.


\\mypcname\c$

But it returned a popup screen with the following message.

"The system detected a possible attempt to compromise security. Please contact the server that authenticated you"

Obviously this was some kind of mistake and from searching the web it seems the problems comes about due to the machine I'm using to access the remote PC which was on a domain and was using different credentials than what I was trying to use to access the resource.

From Microsofts own Knowledge Base article 938457: http://support.microsoft.com/kb/938457


Symptom: When you try to include security settings for a user from a different domain in a local domain folder, you receive the following error message:
The system detected a possible attempt to compromise security. Please ensure that you can contact the server that authenticated you.


Note: This problem may also occur when you try to browse the Active Directory directory service listings for the nonlocal domain.


Cause: This problem occurs because the network firewall filters Kerberos traffic.


Resolution: To resolve this problem, configure the network firewall so that TCP port 88 and UDP port 88 are not blocked for either domain.


My Firewall was not blocking these ports but I had no idea what had happened the other end on the servers at work.

To get access back I tried terminal servicing into a different computer from my laptop which I knew I had access to. I could gain access to this PC.

Once I had remotely accessed another computer on the network I ran the following reboot command which when run from my own laptop gave me an "Access Denied" error.

I ran the reboot command

shutdown -m \\mypcname-r -f

I then tried pinging the PC from my laptop and couldn't access it so I knew it was rebooting.

After a while the PC came back online and I could re-gain access to it.

I checked the event logs on both machines and found the following items of interest.

On the Remote PC (I couldn't access)

The Terminal Server security layer detected an error in the protocol stream and has disconnected the client. Client IP: 10.0.9.121.

That IP relates to our server that manages domains om our network.


From looking at the event log on my own PC I could see the following errors at around the time I tried remotely accessing the work PC.

08:32.01
The server could not bind to the transport \Device\NetBT_Tcpip_{AE7A7B4B-3EED-4D2A-B123-1A4F4AB04698} because another computer on the network has the same name. The server could not start.

08:32.03
CoID={C5816EC8-C2E8-4710-A412-F7ECDBC25C42}: The user me successfully established a connection to OurCompanies VPN using the device VPN3-1.

08:32:08
The time provider NtpClient is currently receiving valid time data from domainserver.domain.company.co.uk (ntp.d|0.0.0.0:123->10.0.7.1:123).

08:32:12
The server could not bind to the transport \Device\NetBT_Tcpip_{AE7A7B4B-3EED-4D2A-B123-1A4F4AB04698} because another computer on the network has the same name. The server could not start.

08:33
The password stored in Credential Manager is invalid. This might be caused by the user changing the password from this computer or a different computer. To resolve this error, open Credential Manager in Control Panel, and reenter the password for the credential DOMAIN.COMPANY.CO.UK\me.

08:33.11
The server could not bind to the transport \Device\NetBT_Tcpip_{AE7A7B4B-3EED-4D2A-B123-1A4F4AB04698} because another computer on the network has the same name. The server could not start.


I have since managed to reboot my work PC and home laptop and connect successfully but I hadn't changed my password so I guess it was an issue at the company on their network that caused the problem and looks like an issue with the domain controller and Kerberos which is a network authentication tool designed to use strong authentication for client/server applications by using secret-key cryptography.

Here are some helpful articles related to the same subject if this method doesn't fix the problem for you.

http://www.bluemoonpcrepair.com/wp/?p=20

http://support.microsoft.com/kb/938457