The April 2019 upgrade for Business Central is coming soon, and with it there are some changes to give you more visibility and control over the upgrade experience for SaaS tenants. Keep reading for an overview of the changes you can expect in the process to help you prepare for the upcoming upgrade to your tenants. Notifications The first thing you should do in preparation for the upgrade is ensure that at least one individual or distribution group has been entered as a notification recipient in the Business Central Admin Center. With the October '18 release, we introduced a single notification that informs administrators when a Business Central environment has upgraded successfully to the next version. Beginning with the April '19 release, we will also send notifications for preview version availability, upgrade scheduling, extension validation, and upgrade failures. These notifications are sent to the recipients entered on the Notification Recipients page of the Business Central Admin Center. There must be at least one person listed on the page to receive notifications of these tenant events. Scheduling the Upgrade The annual upgrade cycle will continue with semiannual major updates in April and October, with minor monthly updates in the months when there is not a major release. For the semiannual major upgrades, you will now have the option to schedule the upgrade for each Business Central environment on a date that works best for you, within a defined date range. The upgrade date range will vary, but will typically be about a month. When the upgrade is ready, you'll receive an email notification letting you know the upgrade date range, and providing a link to the Business Central Admin Center, where you can schedule the upgrade. Just select the Schedule upgrade action on the environment details page to open the pane where you can select your date. The upgrade then gets applied to the environment on your selected date, within the upgrade time window selected for the environment. Note that even if you don't select a specific date for the upgrade, the environment will still get upgraded within the upgrade date range. Environments that don't have a specific upgrade date selected will have the upgrade rolled out to them as time and resources allow. Not selecting an upgrade date does not prevent the environment from being upgraded. Sandbox Testing Prior to upgrading your production environments, you may want to test the new version in a sandbox environment to prepare for the upgrade. We've made a few enhancements to sandbox environments to enable easier testing for extensions and next-release functionality. Upgrade Preview You have the option to create a new sandbox on a preview of the next release of Business Central. When an early build of the next release is ready, we’ll make it available in preview. Then, when creating a new sandbox environment in the Business Central Admin Center, you will have the option to create the sandbox on either the current production version, or on the preview version of the next release. The preview version is typically made available for sandbox environments about two weeks prior to the beginning of upgrades rolling out to production environments. This gives you the chance to load the next release in a sandbox environment for testing and reviewing the new features that will be available with the upcoming release. Sandbox environments created as a copy of your production environment will continue to be created on the same version as the production environment being copied. Multiple Sandboxes You can now have up to three sandbox environments at a time per tenant, each of which can be given a unique name. Note that the sandbox functionality itself is still in preview, and there is currently no additional charge for creating and using sandbox environments. However, when we have finalized sandbox functionality, there will be a yet-to-be-determined subscription plan for the use of sandbox environments in the tenant. Also note that the ability to create multiple named sandboxes is functionality available in the April release. You will only be able to create a named sandbox if the environment is being created on version 14.0 or greater, for example, on a preview version of the next release. Once all of your environments have been upgraded to the April release, you will have full access to the multiple sandbox functionality. Extension Enhancements with Sandboxes There are also several enhancements to sandbox environments related to the management of extensions. When creating a sandbox environment as a copy of your production environment, per-tenant and AppSource extensions are also copied to the new sandbox environment. When sandbox environments are upgraded, both per-tenant and AppSource extensions are upgraded with the sandbox environment. There is no longer a need to re-install the extensions following the upgrade. You can now upload per-tenant extensions using Extension Management in a sandbox environment, with the option to target the current version, the next minor version, or the next major version. Extension Validation A major cause of delays in the upgrade process is extensions installed on an environment that are not compatible with the next version of the base application. The environment can’t be upgraded so long as there are any extensions that are dependent on schema elements that have changed in the next release. So, we’ve created an automated extension validation service that compares dependencies of installed extensions to the schema of the next version. If there are any elements that cause the extension to be incompatible with the next release, you’ll receive a notification letting you know the incompatible extension, and the details of what needs to be changed for the extension to upgrade successfully. This notification is sent to the email addresses listed as notification recipients in the Business Central Admin Center. So, as noted earlier, please make sure you have at least one address listed there so we can make sure you are getting these notifications. Next Steps With the enhancements to the upgrade process coming, here are some next steps we recommend: Go to the Notification Recipients page of the Business Central Admin Center, and make sure you have at least one notification recipient listed for each of your tenants. Review The Business Central Admin Center documentation for more detail on tenant administration. Start planning your upgrade for the April 2019 release. As always, provide feedback on how we can improve this experience on the Dynamics 365 Business Central Ideas site.