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:
Delete the ChromeHTML key from HKEY_LOCAL_MACHINESOFTWAREClassesChromeHTML
Export the HKEY_LOCAL_MACHINESOFTWAREClasseshtmlfile key to your desktop, call it reg.reg
Open the reg.reg file in notepad and do a word replace of htmlfile to ChromeHTML
Save the notepad file and exit
Run the registry file which will import the new key
Once users close Outlook and other Microsoft Office programs, the problem will be resolved.
Many users have reported that they are having problems installing .net 3.5 SP1 or .net 3.0. There are many issues that can cause this problem. After much testing we have found the best way to fix this problem is to run the .net cleanup tool and install .net 3.5 SP1 once it has finished. We recommend removing all .Net versions on your system unless you specifically need one.
[Update: This can also be caused by IIS being installed. If you do not require IIS, uninstall it then try installing the .Net 3.5 SP1 framework again]
Instructions 1. Run .Net Cleanup Tool 2. Remove all versions of the .Net framework from your computer 3. Restart your computer 4. Install .Net Framework 3.5 SP1