Symptoms
You upgraded from K2 4.6.x to 4.6.9 or newer. After a while K2 smartforms stopped working in IE11 for all users displaying "Your browser is not supported" page, and when user tries to enable Enterprise Mode in browser "Your browser's compatibility mode is not supported." IE doesn't display any indicators of enabled Compatibility or Enterprise Mode.
Diagnoses
Starting from 4.6.9 IE8 is no longer supported as Runtime browser for K2 SmartForms along with any compatibility modes forcing recent versions of IE to emulate IE8.
The only possible cause of getting "Your browser is not supported" message is IE Enterprise Mode configured and applied to your K2 domain/URL.
You may be confused, as when Enterpise Mode Site List is configured you may not get any conspicuous indication that you actually have it enabled from the browser UI side (i.e. there is no enterprise mode icon being displayed in the address bar). Also when client side Enterprise Mode settings are not locked out you do not see contents of your enterprise list from this GUI, and moreover are able to make correct changes (Edge or Default mode) and make SmartForms working for a short period of time, but it will be promptly overridden by Enterprise Site List during group policy refresh cycle (by default the computer tries to update Group Policy every 7 seconds).
Consequently at the first glance it may seem that K2 smarforms return "Your browser is not supported" page for IE11 which has both Compatibility Mode and Enterprise mode disabled:
Emulation TAB of F12 Developer Tools in IE shows document mode "Edge", but on console tab of F12 tools it is possible to see the following:
HTML1122: Internet Explorer is running in Enterprise Mode emulating IE8.
This is also clear indication that IE11 Enterprise Mode was configured through group policy (specifically Enterprise Site List is configured).
This problem is generally caused by the website/intranet URL being placed in one of the following locations:
- Compatibility Mode List
- Internet Explorer Intranet Zone
(with Display intranet sites in Compatibility View setting enabled) - Enterprise Mode List
On corporate networks, these compatibility view settings are often controlled centrally via group policy.
You can try to exclude your site from the Intranet zone. But normally the list of domains which belong to the Intranet zone is also controlled by the group policy. To see the list of domains that belong to the Intranet zone, go to:
Tools -> Internet Options -> Security -> Sites -> Advanced
If the list contains your subdomain and is greyed out, then you will not be able to override compatibility view until your AD DS administrator allows it. In this case you really need to contact your network administrator to allow changing the compatibility view settings specified in group policy.
Resolution
In case you have Enterprise Compatibility list configured through group policy you have to make sure that K2 smartforms domain/URL is set not to use any emulation modes available in Enterprise mode options. It means that you have to configure it as Edge (available for Windows 10 clients only) or Default (available on Windows 10 and earlier versions of Windows, means no emulation mode).
K2 SmartForms browser settings requirements:
http://help.k2.com/kb001704
In order to quickly check Enterprise Site List settings for different domains you can do the following:
1) Identify your site list location by issuing the following in PowerShell (depending on your GPO settings it maybe necessary to change "hklm" to "hkcu"):
(Get-ItemProperty -Path "hklm:SoftwarePoliciesMicrosoftInternet ExplorerMainEnterpriseMode").SiteList
2) Use the URL/path obtained to open sites list XML file using your browser or Windows Explorer.
3) Browse through XML file to confirm what is configured for your K2 SmartForms URL/domain
If wrong settings are present in site list work with your Active Directory administrators to adjust settings in Enterprise Site List.
Further information on Enterprise Mode: IE Enterprise Mode in a Nutshell
List of HTMLxxxx codes can be found here: Console error messages in F12 developer tools
