When you add a new IP address to your current server configuration for internal use and navigate to K2 sites, K2 Designer operates normally, however the management site and Runtime sites do not render correctly.
When troubleshooting you will see runtime errors when using the browser debug tools within fiddler or within the Developer console settings (F12). This will be displayed as:
"500 Internal server error"
To resolve this issue please follow these instructions:
1. Go to C:\Program Files (x86)\K2 blackpearl\K2 smartforms Designer.
2. Backup your web.config.
3. Search for UseBundledFiles key and switch it to false.
4. Search for Forms.PostRenderCombining.Enabled key and switch it to false as well.
5. Please carry out the same steps for the Runtime URL as well - C:\Program Files (x86)\K2 blackpearl\K2 smartforms Runtime
6. Run an IISReset and clear your browser cache.
7. Navigate to the Management page and Runtime sites to see if they are now in a functional state.