Fixing SharePoint

Since this is the backbone of SharePoint 2013 based workflows, I think Microsoft needs to make this application more mature and errors should be more clear and point to the root cause. Anyhow, that was just a suggestion, who cares. :) We have came across this error while it was working fine till yesterday. We removed the bindings and when it was needed to register the workflow again, this happened. Workflow Manager Error: WARNING: Overwriting existing scope named "SharePoint" in the workflow server. If another SharePoint farm was registered using this scope, that farm may not be able to continue working with the workflow server unless re-registered under another scope name. Register-SPWorkflowService : Failed to query the OAuth S2S metadata endpoint at URI ' https://mysitename.com/_layouts/15/metadata/json/1'.  Error details: 'An error occurred while sending the request.'. HTTP headers received from the server - ActivityId: 87239463-ea78-4ccc-81cd-a1ec0b903b

This is pretty much something that I have not found in a direct way on internet so I thought I must write about it and make someone else's life easier someday. Scenario:  I have scenario where my customer has SharePoint Online portal with multilingual support and some custom developed web parts. During the development phase, the tenant was different and I was able to redirect user to MyAccount so he can change the preferred language,  but this setting was not available on customer's tenant. The reason was, we had Azure AD profiles while customer has synced them from local AD so this setting was not available. I recommend you to check out my this post about the language switch issue that I faced. Problem:   Since the manually preferred language change option was not available, we need to find another way where user can switch to any other language. In my case it was switch to Arabic from English. Solution Overview: Since the preferred way to make the language switch should be le