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.

restriction-errorpng

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 fromĀ HKEY_LOCAL_MACHINESOFTWAREClassesChromeHTML
  2. Export theĀ 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.