I have been working on migrating an old Episerver site to Azure and was having issues starting the site localy after configuring it to use Azure blob-storage. At startup I was getting "The remote server returned an error: (403) Forbidden." as the framework was calling the CreateIfNotExists-method.

Everything seemed to be correctly set up so finally i set up Fiddler to see what was happening. 

I found that there is a http-header (x-ms-meta-EPiServerAzureCreatedByAccount) sent to the service that contains the app-pool name and in my case that name contained a swedish character. Http-headers should only contaion ASCII-characters so this made the request fail.

This happened happened only when creating the container the first time.

After renaming the app-pool everything started working...

Just a heads up to everyone, dont use non ASCII-characters in app-pool names :)