Error: 417 “Expectation Failed.”

I upgraded a site from 7.0 to 7.5 and i assumed all went well until i try and Save.

When i try and save nothing is listed in the logs, but in the console i see a non existent save path along with the error “Error: 417 “Expectation Failed.””

I have tried the web.config change found here

I have also tried to save all datatypes again and no errors were generated and nothing listed in the logs/server logs.

This happens on EVERY option under Settings when saving.

I then read that it could be a .Net FW version issue/corruption so i tried a different server and same problem although another site works fine.

The original site version works fine too.

I uninstalled all add-ons and that didnt resolve.

Does anyone have any clues on how i can narrow this down to establish the issue?


This is a companion discussion topic for the original entry at https://our.umbraco.com/forum/99911-error-417-expectation-failed