Issue
You are unable to access any K2 site after an installation.
Error
Could not load file or assembly 'System.Xaml.Hosting ....' or one of its depenedancies. Either a required impersonation level was not provided, or the provided impersonation level is invalid. (Exception from HRESULT: 0x80070542)
(http 500 error)
Resolution
This issue is linked to permissions in IIS (Internet Information Services) and not in K2.
Add the group IIS_IURS by following these steps:
A. Go to Start > Administrative Tools > Local Security Policies > Expand Local Policies > select User Rights Assignment
B. In the right pane, double-click Impersonate a client after authentication
C. Click on Add user or Group
D. Select the IIS_IURS and click ok > Then apply
Additional Information
- There were no errors found in the Installer trace logs.
- The required permissions based on the documentation were applied
- The assembly system.xaml.hosting.dll has the correct version and can be found in the GAC_MSIL folder
https://help.nintex.com/en-US/k2five/icg/5.5/default.htm#plan/required-permissions.htm
