Is there is a way to stop this error when hosting in Azure on an App Service: System.IO.IOException: The process cannot access the file 'C:\\home\\site\\wwwroot\\App_Data\\TEMP\\NuCache\\NuCache.Content.db' because it is being used by another process. Thanks

Have you set the azure sepcific options? https://docs.umbraco.com/umbraco-cms/fundamentals/setup/server-setup/azure-web-apps#recommended-configuration I think you might be missing the local storage temp location? As your path there looks to be the SA N filesystem, rather than the web head local temp.

Sorry to be a pain - do you know what this would look like in 8?