Exchange 2013: ECP double login, error 400

After an upgrade of Exchange 2013 from CU1 to CU2 we could no longer access the ECP part of Exchange. OWA worked fine. We got a blank screen with bad request, error 400.

After a lot of searching, it looks like the upgrade for Exchange wipes out the web.config file which has all the settings for authentication on ECP.

See the following:


Be aware that this is incorrect after an upgrade. Set the authentication of basic to true again to ensure the setting is correct (note form based authentication is turned off because we use TMG).

Also make sure your internal and external url for the ECP directory is reset, as this is also wiped.

This is a known bug. See KB2871485.

Outlook: the operation has been canceled due to restrictions in effect on this computer

That’s a long title.

We’ve had this issue on a Windows 2012 Terminal Server. When users click on any type of hyperlink in Outlook (or any other Microsoft product), it gives this error.


This issue is quite interesting. It our case, it has been caused by removing Chrome from the system. But it did not uninstall properly, leaving un-removed registry keys all over the place.

What happens is, when Chrome is installed, it uses a class handler called ChromeHTML. When you click a link, Outlook looks for this class in the registry. If Chrome has not been removed correctly, you will get error above.

The method of fixing this would be to change the .html class under each HKEY_CURRENT_USER, but this is a headache. The better way is to copy htmlfile class, delete the old ChromeHTML class, and reimport htmlfile class as ChromeHTML. This sets ChromeHTML as Internet Explorer, fixing the issue for everyone.

The steps to fix this are as follows:

  1. Delete the ChromeHTML key from HKEY_LOCAL_MACHINESOFTWAREClassesChromeHTML
  2. Export the HKEY_LOCAL_MACHINESOFTWAREClasseshtmlfile key to your desktop, call it reg.reg
  3. Open the reg.reg file in notepad and do a word replace of htmlfile to ChromeHTML
  4. Save the notepad file and exit
  5. Run the registry file which will import the new key

Once users close Outlook and other Microsoft Office programs, the problem will be resolved.

Office 2013: Input lag on terminal servers (Word)

We have a shared environment which we have had issues with lately when customers on slow connections have input lag when using Microsoft Office 2013 applications, specifically, Word.

After much research and testing, we found this issue was to do with Hardware Acceleration that is enabled by default within Office 2013. This is great if you are on a normal desktop/laptop, but not so good on Terminal Server/Remote Desktop Services.

Office 2013

To disable this in word, do the following:

  1. Click File > Options
  2. Click Advanced
  3. Scroll down to Display
  4. Tick Disable hardware graphics acceleration


Group Policy

For Group Policy, you need to have the following settings set:


Hope this helps 🙂