Hello,

I hope I am in the right place. We have quite a few clients in which we had upgraded them from DNN 6 to DNN 8. However we are now having issues with a few of them being unable to add new/existing modules or edit the pages. It results in https://website.local/folder/DesktopModules/internalservices/API/controlbar/ToggleUserMode 404 (Not Found) and refreshes the page.

From googling, we had hoped that changing the controlpanel from ControlBar to Ribbonbar would workaround the issue as we had found it had fixed someone else's issue previously but unfortunately when it comes to actually changing the page it brings up the same error.

We have also tried <modules runAllManagedModulesForAllRequests="true"> it only hid the error. 

The event log does not provide any information.

Any assistance on where I can look next is greatly appreciated.

We did do the suggested upgrade path and we do have backups.

I did check the files on the site in the mean time. Well, actually I replaced all but web.config from an fresh/blank upgrade. No changes.

Will go through restore and re-upgrade tomorrow, it is possible I missed something, I'll provide an update with the results and any install logs errors I find.