I will try and explain my issue as the title doesn't really justify the error

I have been programming DNN and building websites with DNN for about 3 years and this is the first I have come across my error.

I had two tabs setup, to make this easy to follow I will call the first page Parent and the second Child. These tabs were added to the site as Parent and Child so that the Parent option displayed in the menu all the time.

When adding a module to either page, the module was not added. Refreshing with Ctrl + F5 made the item appear, but doing the same again made this disappear. Going to a different page to see why this was, the Parent disappeared from the menu.

Then clicking on Admin->Pages returned the menu item, but did not display the tab in the list of pages. Refreshing this page showed the two pages in the list of pages. Clicking on either the Parent or Child in the menu now re-directed back to the home page.

After several attempts of going round in circles I decided to delete the pages. After pressing delete tab in the admin->Pages options they both returned now and again. I removed the reference to the tab completely from the tables and yet still the pages appeared in the Admin->Pages list(delete this tab now returning null reference error)

Has been about an hour now and the issue has since passed but I was wondering if anyone had any insight into how this can occur or anything I might be able to try as this is still affecting adding new pages(not showing them and not adding to the Admin->Pages etc etc)((Same issue with adding or editing modules))

Any and all information is welcomed

Thanks

Jason