Operating system error 50(The request is not supported.).

Hello, 

I know this has been asked before but I'm still getting ab error after starting from scratch. 

SQL 2017 (Ent) 

I want to backup to Azure storage using a SAS that has one year left before expiring.  I created a new credential. 

and then the backup and error. 

The SAS has one year to run, I created a new container called 'daveg' in the storage account and I used SAS token for the password

Any ideas what might be wrong. 

Thanks 

PS - Does anyone else find this MSDN text editor changes font size on a completely random basis?