If you are upgrading your Windows 10 PC, such as moving to a Surface Pro 4, Surface Book, or adding your account to any other PC, you will likely have to download many of your purchased apps from the Microsoft App Store. These tips are particularly helpful if you receive error code 0x80240438 and the message indicating "The problem is at our end ..." when downloading apps. If Microsoft Store Apps are not downloading, check these things. 1. OneDrive may be updating. Store apps are not downloaded until OneDrive reaches "Up to date". Remedy: Wait until OneDrive finishes, or right-click the OneDrive notification icon and choose "Exit". OneDrive will restart next time you login to your PC. Open the Store. 2. Windows Update is active in an update, or hung up on trying to complete an update. Remedy: Allow Windows Update to complete, or restart the PC and do not visit Windows Update. Open the Store immediately after your restart. 3. You are not Verified on your PC. Remedy: Settings, Accounts, Verify 4. Your PC is not listed under Devices in your Microsoft account, or your Device list has become corrupted. Remedy: Login to www.microsoft.com with your account information. Visit Devices. Clean up the list of your previous machines if necessary. You may even remove your current PC, and re-add it. You will need the serial number of your Surface device, or PC. Another way to re-add it is to just login with Windows 10 and Verify (step 3). 5. Mail and Calendar app is synchronizing. Remedy: Wait until Mail and Calendar finishes, or close the App. Start the Store immediately. Here's a good one I have found works, when ... 6. All the above options have been exhausted, and Store will not download your purchased apps. Remedy: Buy an additional app. Find something cheap that you may actually want, like a Weather or Calendar app. Apparently, when Microsoft visits your account payment arrangements, then adds an item to your list of purchased apps, the list is refreshed and downloads resume. Good game, Microsoft.